Hey.

The Eligiblity criteria of BITSAT states that you the candidates appearing for 12th/equivalent qualifying exam in 2019 and the ones who passed the qualifying exam in 2018 are eligible. Those who passed in 2017 or before will not be eligible.

In case, you taken more than one attempt in their 10+2 or equivalent exam, then only  your latest performance will be considered, provided this attempt has been for the full component of subjects/ courses prescribed. 

You also require a  minimum 75% marks in aggregate in Physics, Chemistry and Mathematics/ Biology and minimum 60% marks in each of Physics, Chemistry, and Mathematics/ Biology subjects individually.

Best of luck!