Dear

Engineering having plus point, Recognition in job market , opportunities and exposure too.
So According to me you should complete your class 11 and 12 then try for Engineering from good Universities.

All the best

Prefer engineering , polytechnic will give you diploma but engineering gives you degree . Other thing is devoting 4yr for engineering  is better than  three yr in diploma which is equal to first yr of engineering.

Polytechenic is base for engg