Planning to study MS in Petroleum Engineering.

Applying for Fall 2013 intake

CGPA : 6.44(second class) In B.E Mechatronics Engineering
GRE : 327 (Q-166 , V-161) AWA -4.5

What Universities can I get into ? And what should be the ambitious Universities that I should apply to ?
Or will it be easier for me to get into good universities after working for 2-3 years due to my low academics ?