Hi pal,

Entrance exam conducted for checking your basic ability in particular subject, the fact is only some topmost universities conduct entrance exam. Du gives admission on basis of bsc merit but only for Delhi university students.
For others du conducte entrance exam.i like to suggest you to go for entrance test because that will lead you toward bright future.
Here is list of some entrance test for masters.

1.jam.

2.jest.

3.du entrance test.

4.tifr.

5.nisar.

Hope this will help you.

Good luck.