Hii..

As you ask about best polytechnic college after 12th so there are some colleges:

• Government Polytechnic Mumbai
• Angel Polytechnic
• KIIT Polytechnic
• Anjuman Polytechnic
• Government Polytechnic Pune
• VPM's polytechnic Thane
  

for more information click here:
http://recruitmentresult.com/top-polytechnic-colleges-in-india/
All the best!!