Engineering Undergrad to Physics Grad

I am presently an undergraduate studying mechanical engineering and I am interested in applying for physics graduate programs. Since I hail from a different stream I am a bit worried about my likelihood of obtaining an admission. Although my major is different I have made sure to do the physics undergraduate courses online via platforms such as Edx and Coursera and eventually taught two certified summer schools in General Relativity and a certified-credited course on Classical Mechanics at my college. I have written two books, one on Differential Geometry and another on General Relativity, both published on Amazon and are selling successfully worldwide. I am presently in a Fuzzy Graph theory research group and we will be publishing our work soon (2-3 months) and hopefully I do get an internship program for which I have applied (which could strengthen my profile).
Rather than asking the dubious question of what my chances are, I want to know if colleges consider a stream-changing student like me and if I can take a shot at an international top school.

Stream-changing students are common, but it really is a case-by-case decision for most departments.

@NaveenBalaji - Welcome to the Forum!.

I agree, we have admitted a number of engineering students to our physics graduate program at Illinois Tech. They usually need to take some remedial undergraduate courses before starting on graduate physics courses but the ones who have come usually have done very well. Yours is a situation that a number of students in countries outside the US find themselves in because once they start in a curriculum, it is impossible to switch. This is a bit easier in the US because the first two years are similar in engineering and physical sciences.

I should also mention that self-published texts that are not subject to peer review in any form are unlikely to move the needle in any way.

Although the FAQ sections of university admissions mention that there are no required courses for the admission to the program I would like to know if there is a provision for me to avail the necessary courses along with the graduate program. When I had written my concerns to few universities they did mention that doing well on the physics gre would imply that one had reasonable knowledge in the undergrad curriculum.

You’re asking a question whose answer will different from one university to the next.