The Birla Institute of Technology (BIT) Patna's admission process for B.Tech programs is based on JEE Main scores through Central Seat Allocation Board (CSAB) or Joint Seat Allocation Authority (JoSAA).you need to appear for the this test and get valid score apply if they selected you on jee mains score yo get admission in the college.to know about jee mains

https://engineering.careers360.com/exams/jee-main