Will a good GRE Computer Science subject test score overcome a "weak" academic record?
Regarding research, I don't have possibility of doing any research and it is not a top priority here, so we aren't provided opportunities for research.


For purposes of graduate school admissions, any self-directed intellectual activity counts as research.  Have you contributed to any open-source projects?  Have you written any Android or iPhone apps?  Did you solve all the double-starred problems in Hopcroft and Ullman?  Did you write a confluently persistent graph data structure library?  Did you participate in (or better yet, coach for) the International Olympiad in Informatics?  What about Google Summer of Code?  Do you contribute regularly to a StackExchange site?  Have you rebuilt a pinball machine?  These are all real examples.

Research opportunities are not something you're provided; they're something you hunt down and kill.