I think you need these two basic certificates.
- Jaati praman patra( cast ccertificat) this gives the proof that you belongs to obc category.
- Income certificate: this justifies the income of you parents which is required to know if income is less than 1 lacs or greater than 6 lacs or in between that .
This is required because when you will pay you fee the if you are having income less than 1 lacs then you come in category of MEB (most economically backward) then full remission of tution fee will be there and if greator than 1 lacs but less than 6 lacs then some part of the fee will be returned.
I think these are the major documents while other documents will be your
1.Final freezed college letter
2. 12th marsheet
3. 10th marksheet
4. Photos.
Best of luck _/\_