Hello.
There are  many top MBBS colleges but one of the top college is AIIMS, New Delhi , admission in this college can be done through AIIMS entrance exam, and generally most of the top MBBS colleges takes admission through NEET exam so you can appear for this exam too., If you want to see  the list of top MBBS colleges in India then you can go with the below link :
https://medicine.careers360.com/colleges/ranking
On the above link you can also see the exams accepted by the colleges for getting admission in it.
Best of luck.