Hi Shekhar

I am providing you with the names and links of top engineering exams for engineering :

JEE Main - https://engineering.careers360.com/exams/jee-main

JEE Advanced (only if you qualify in JEE Main with a specified rank) - https://engineering.careers360.com/articles/jee-advanced

SRMJEEE - https://engineering.careers360.com/articles/srmjeee

BITSAT - https://engineering.careers360.com/articles/bitsat

VITEEE - https://engineering.careers360.com/articles/viteee

Refer to the link below to know more  - https://engineering.careers360.com/exams

The big exams in Medical are :

NEET - https://medicine.careers360.com/articles/neet

AIIMS - https://medicine.careers360.com/articles/aiims-mbbs

JIPMER - https://medicine.careers360.com/articles/jipmer-mbbs

Refer to the link below to know more,

https://medicine.careers360.com/exams

You will get the important dates in all the links given above.

Please be specific about Science exams to know better.

Thanks!