dear aspirant,

Yes you can apply for CSAB-2019.

the elegibility criteria is mentioned below :

Qualifying Exam: Candidates must have qualified JEE Main 2019 with valid scores.

Domicile: Candidates need to belong to the  mentioned States and Union Territories.

Qualifying Marks: Candidates should have obtained minimum 45% marks or should be in top 20 percentile in their class XII exams as conducted by their respective boards.

Candidates belonging to SC/ ST categories need to have 40% marks in the same criteria.

Qualifying Subjects: The marks secured in the following subjects will be considered -

Physics, Chemistry, Mathematics and language.

for more details check the link : https://engineering.careers360.com/articles/csab

hope this helps.