• Your 12th standard qualification details
• Your Permanent Address
• A valid E-Mail Id & Phone Number
• Credit Card/ Debit Card/ Net Banking Login id & Password (For Online Mode of Payment)
• Confirmation Receipt of Pay-in-slip (for Offline Mode of Payment)
• Visit the below given link for step to step procedure of filling bitsat application form:

You will required below things to fill BITSAT Aplication form 

- 10th class marksheet

- Debit/Credit Card

- Digital/scanned Photograph 

- Digital/scanned Signatur

To know how to fill BITSAT form you can refer below link

https://engineering.careers360.com/articles/how-fill-bitsat-2018-application-form

Good Luck!!