Hi Kavita,

A bachelor of Computer Application, or more commonly known as BCA, is a three year program. This degree is primarily focused on subjects such as software, databases, and networking. In general, computer science degrees tend to focus on the mathematical and theoretical foundations of computing.

Following is subjects included in entrance exam :

Mathematics, Logical Ability & Reasoning , Computer Awareness and Information Technology, General Knowledge, English Language & Comprehension.

Actually both courses are good at there own place so you have ti decide it according to your interest. 

All the best.