Can we send our research paper to two IEEE conference simultaneously, and then after acceptance, decide which conference proceedings to publish it in?
It is considered unethical in the academic community to submit a paper for simultaneous review at multiple venues (unless it is explicitly permitted by the publications, and you disclose this on submission).
The IEEE guidelines on multiple submission prohibit multiple simultaneous submissions:
Authors should only submit original work that has neither appeared elsewhere for publication, nor which was under review for another refereed publication.
The guidelines further specify that failure to disclose, on submission, that the work is under review for another publication, can result in (after multiple offenses)
suspension of publication privileges in all IEEE Publications for 1 year and rejection and return of all papers by the author(s) that are currently in review or in any IEEE publication's queue (papers may be re-submitted after suspension term has expired).
In addition, engaging in this practice can irreparably damage your reputation in the academic community.
Short answer is yes, but it is unethical. Even when you read the agreement before submitting your paper it appears that the work should be original, that means that it should have not been submitted to other conference or journal. You must put in the shoes of the reviewers, in one hand you make them waste time by reviewing one paper that is already being checked up in another conference. Also you are getting one available spot that could be filled by another research paper by another person.
One advice, take your work in academia more seriously than just submitting like if its a game.
I understand your motivation, because IEEE only looks into how to protect reviewers even though many of them are not competent or up to the level of the submitted manuscript. Such incompetent reviewer will normally ask for pointless revision or may reject the paper if s/he doesn't understand the paper main idea and contribution even though the other reviewers of the paper could praised it and accepted it.
Such incompetent reviewers usually will not understand the paper because they accept reviewing papers that are not within their subdomain or area of expertise to just adding service part to their CVs.
Unfortunately IEEE has a serious problem in its current procedures of selecting reviewers which is done randomly, and that means the editor will look into the reviewers pool of the journal and sends some invitations randomly for possible reviewers. The issue will be exaggerated when that reviewer accept and judge your work regardless of whether they are qualifying for that or no. Unfortunately, they can hurt you by judging wrongly your work and escape simply because their identity are protected by the Journal.
Also, IEEE has no real commitment to any time span of the reviewing process, they may announce the reviewing process takes three months for example, but actually they may let you stuck awaiting for the decision much more time. Therefore, IEEE violates what it should be a fair process for publication in many dimensions, and if your paper received three reviewers decision, for example two acceptance and one rejection, IEEE Editors normally go with the rejection and neglect the majority decision opposite to any fair judgment system . They should go with the majority of reviewers decisions but unfortunately they don't. So I can't say it is not possible solution to overcome such a pain by trying for multiple submission because you also can't put your future under such messy, uncertain and unfair circumstances. You can be a student who needs one more paper for graduation, or you can be a faculty needs one more paper for promotion, or you can be a graduate student needs one more paper to get hired or to keep your position, and if you lost that chance of publication on time because of some incompetent reviewers then the impact could be huge on your life.
Those incompetent reviewers are actually very bad people who may destroy other people life and career just to add some lines in their CVs reflect their service as reviewers for journal x or y.
I don't encourage you to violated any journal rules, but act in a smart way, and don't make mistakes can be taken against you. On the other hand protect your self from such possible unfair environment. try to search for journals or conferences that accept multiple submission.
The process of submit paper should be similar to the process of sending applications for admission to universities. So you are able to send multiple applications to many universities but in the end of the day you will accept only one offer when offers come. IEEE should also do the same to protect authors for wasting time and efforts, but unfortunately they don't.
Therefore, do what is best for you because publishers especially IEEE only care about their regulations and reviewers and their CVs update with the editorializing or reviewing service. Your career growth and future plans for sorry is not among their concerns at all.
IEEE allows certain authors to submit and publish work that is currently under review.
IEEE likewise allows certain authors to submit and publish work that was previously published.
IEEE likewise allows certain authors to submit and publish work that was published by other persons.
Numerous examples can be found by searching the web.