As you mention your rank as a 71 in appgecet in EC paper and also your category as OC ....as your category is OC there will some difficulties to get top colleges as your category also play important role.... but may you also get these colleges if you wait till last counselling...
But there are other top colleges which you can get easily with your rank ..
- G Pulla Reddy Engineering College
- Sri Vidyanikethan Engineering College
- RVR and JC Engineering College
- Sri Venkateswara University College of Engineering
All the best!!