My wbjee gmr rank is 33091 and my sc rank is 2451 . I'm from home state. can I get cooch Behar or Purulia in cse branch?

As you have reserved category rank, you can try for government colleges. But your reserved rank is too high to get into Coochbeher government engineering college. Moreover, computer science branch gets filled quickly, so I thnink you have less chance to get into CGEC. Though you can wait for third round.
Besides,  purulia government engineering college is newly opened. So the cutoff is not so high. The first batch hasn't placed yet. So you have  a chance to get into that college.
Lets hope for best.
Good luck..