After I Have Passed 12th And now joining college. I have done D.T.P Designing Course and in that only I have to go Ahead.

You can pursue a Graphic Design or visual communication course from NID, MIT ID etc

If you're creative, you can also consider going for Design and Animation. However, you must first check if you're suited for Animation. Animation is an art form and a very demanding career. It has ample opportunities for the creatively talented people. Typically you should have good sketching skill