I would probably advise you not to leave the opportunity of studying in Bits Pilani just for financial constraints.
Firstly, Bits Pilani is one of the topmost institutes of the country, having been ranked alongside many of the IITs in the past and continuing to do so in the present.
Secondly, academic flexibilites which includes the dual-degree system and many diverse electives has lent the course structure a uniqueness not usually seen in other colleges.
Thirdly, the selection process throuch BITSAT and direct admissiom to board toppers has ensured a steady inflow of meritorious students. No reservation and no donation seats is one of the best things about the institute.
Now I would like to talk about how you can actually solve your problem.
Merit-cum-Need scholarship is awarded to meritorious students with annual family income of less than 8 lpa. Other than that, merit scholarship is awarded to the top 1% students based on cgpa. This is excluding the educational loans that you can get from banks.
The matter of choosing college is a very tricky affair. The branch you are getting, your interests and overall the positives you want to extract out of your college life are some parameters you need to include in your assesment of a college.