Hey,
Here is the list of some of the best polytechnic courses in India:
1.Polytechnic Automobile Engineering:The vehicles,as you know are the integral part of our lives.So,this course gives you the opportunity to study about vehicles vis-a-vis their design,manufacture and other elements.
2.Polytechnic Computer Science Science Engineering:
This field will prepare you to work as web designer,web developer or programmer.
3.Polytechnic  Civil Engineering:
Once you done this course you will be eligible to work as civil engineers.
4.Polytechnic Mechanical Engineering:
You get to learn to design,development and manufacturing the mechanical parts and can work as mechanical engineers in companies.
5.Polytechnic Electrical Engineering :
You learn to deal with the study and application of electricity.
6.Polytechnic in Information Technology :
You can work as IT professionals in different companies.
7.Polytechnic in Aircraft Maintenance Engineering:Though expensive this course opens avenues for you in aviation industry.
So,be sure of your calling and what you are actually interested to do and take up the course accordingly.
Hope this helps.
Good luck