I am a Software Engineer and I have finished BSc in Computer Science and Engineering, currently I am working as well as doing some researches related to Computer Science in my spare time. I am curious to know how I can publish for top journals as a single contributor without any mentors or supervisors. I will highly appreciate if you provide any feed back or reference related to the process.
The answer is simple but difficult.
Write the best papers if you want to publish in the best journals.
There is no bar for being an individual. Do good work. Write it up properly and submit it.
But, to write good papers without any guidance is very difficult. There must be something "real" behind the papers, usually research and that, alone, is difficult. The first paper is the hardest. It gets easier after 10 papers, or so. But if you submit a lot of poor papers to top journals you might get a reputation as a crank. Having people to bounce ideas off of can be a big help.