Hello aspirant,

Before suggesting the books you have to take a decision on which stream you are going to pursue your Higher studies.

Few options that you do after MBBS

MS/MD in pre clinical, para clinical or anything which is your area of interest
Next option is MBA and you can get into administration
Other one is medical law

Take your time an  decide on your interest area. Afterwards, according to your interest its easy to find guidance books to get into top institutions.

Best wishes!!!