Hello Ragu

You will get a bca seat if you will fulfill the eligibility criteria for the course.

You have mentioned that you have completed diploma course , you have not mentioned your diploma score .

Eligibility criteria for getting bachelor's of computer application seat is to have passed diploma in computers with minimum 50 % marks with physics,  chemistry and mathematics,  English as core subjects from  any reputed university

OR

The candidate must have passed class xii with minimum 50% marks in physics,  chemistry and mathematics, English.

You must appear for entrance exam conducted by university or any of the following

Jee mains

Kcet

MHT CET

GUJCET

You may go through the following link

https://www.careers360.com/courses/bca-bachelor-of-computer-applications