I live in US. In some applications it is asking to enter your cumulative and major GPA. However I am wondering which GPA is more important and which one is used for admittance famous graduate schools (Top 10) in engineering program?
First of all, remember that GPA is more of a negative filter than a positive filter. If you do not have an excellent GPA in your relevant major, then you are definitely going to have trouble getting admitted. The GPA outside of your relevant major is less important, but it will still raise major questions if you have, say, all As in major and all Fs outside.
I have a buddy who was an admissions officer some years ago, and he said, "major."
In graduate school, you will be taking mostly courses either in, or related to you major. Therefore, your "major" GPA is considered a better proxy than "cumulative" GPA for a graduate degree.
In graduate school, there is much less emphasis on being "well rounded" and more on "specialization." If your non-major grades are decent, and your major grades are good, that's what counts. My friend had a 3.9 GPA in the engineering major, and only a 3.3 overall.