You can check these colleges for engineering at low fees. 

1) BMS college of engineering, bangBanga

2) Manipal institute of technology, Karnataka

3) The institute of engineering and management ( IEM) , Kolkata

Go through this link for more information:

https://www.quora.com/Which-is-the-best-cheap-private-engineering-college-in-india

hey buddy there are many Engineering colleges in Andhra Pradesh since you have asked the best private Engineering college with low fees .
So I'm mentioning some of the best colleges with minimal amount of fee

SRKR Engineering College
Velagapudi Ramakrishna Siddhartha Engineering College
SVEC - Sree Vidyanikethan Engineering College, Tirupati
R.V.R. & J.C.College of Engineering
SV College of Engineering
GVP College of Engineering (Autonomous)
G pulla Reddy Engineering College
Bapatla Engineering College
Aditya Engineering college
Chadalawada Ramanamma Engineering College
Shri Vishnu Engineering college for women autonomous
Lakireddy Bali Reddy College of Engineering
GMR institute of technology
Audisankara College of Engineering and Technology
Andhra University college of Engineering