Hi aspirant

If you are not looking for engineer point of view then you should go for BCA.As it can save you time .

If you talk about learning almost course curriculum is same for both B.tech in CSE/IT and BCA.

If you have interest in app development ,you can do it without joining even BCA also.You can learn it by yourself if you have programming knowledge.

If you don't have even that join some reputed coaching institute and enroll your self for courses like java at first and then android development.

If you know java well you can directly join Android development either online or offline.

Some offline institute :NIIT (All across the country) ,Naresh IT, DurgaSoft(Hyderabad)

Some online: Udemy,Internshala,Coursera,Edx.org,Udacity,Edureka.

hope this was helpful.