Choosing between Rabindra Bharati University (RBU) and Calcutta University (CU), is not justified, as they are both reputed institutions and have more or less the same performance. 

Their curriculum will be different, along with their teaching style. But both will provide you with similar opportunities after graduation.

CU students claim that it is very difficult to score good marks here, but since the semester system started in CU, it has become manageable. 

So choose the college you feel suits all your requirements, then go for the one. The one thing better in CU is the environment, because RBU has been in constant disputes and political turmoil, which sometimes hampers regular classwork.