Interested in working on polymer science's application in either of the following fields- as alternative energy, energy storage, bio-degradable polymers and eco-friendly polymers.

GRE Score 320 (verbal 156; quant 164)
TOEFL 108 (27 R; 28 L; 24 S; 29 W)
B.Tech in 78.92%(aggregate of 3 years)
Plastic Technology
HBTI, Kanpur
High School 88.2%
Intermediate 84%
2 research interns of two months each from IITK and IITB in second and third year. 1 B.Tech project. 1 B.Tech seminar.
LORs- one from IITK professor, other from IITB professor and other from my college ex-director and professor.
Five paper presentations. Won Two, one national seminar, one at NIT Allahabad.
Good extra-curricular. Moderate involvement in social activities.
Can you please suggest me universities which will be ambitious, moderate and safe for me? I'm really confused.