Hey,

First of all you said have class 12 th in science group with mathematics

Apply for BHU entrance exam whose forms will be out by February mostly.The cost of form is 600 for general .

After that take a bhu entrance exam book of a good publication like arihant ,etc and study it will have previous years question and sometimes even match.

The entrance exam will be held by mid April or May .

Clear the exam .You will get a counseling letter if you clear the exam after which you can complete the admission procedure.

For more detail please visit our link.

https://www.careers360.com/colleges/dhirendra-mahila-post-graduate-college-varanasi

All the best!!!