I have 4 year's gap after PUC science (PCMB). Is B.Sc a good option? If yes, which branch should I go for? Is natural science a good option?

I think you have to go for some professional courses, if age criteria is permiting. Courses like B. Des in Fashion design, Product design, Graphic design, industrial design, interior design etc. are the demanding courses. The top design institutes like NID and NIFT are offering these specializations