Better option is person specific. So depending on your interest any one of this will be the best. In general, if you want to study Computer science in broad perspective starting from Hardware to software then you should opt CSE. But if you are not so interested in the all perspectives and just want to learn specifically about software then Diploma in Software Engineering can be a good option for you.

This is a very rough difference but I think this will give you a idea to differentiate your interest.

I hope this answer helps. All the very best for your future endeavors!