I am a 2nd year Btech CS student. What are the various computer courses that i can study to improve my chances of landing a job.

First of all, concentrate on your B.Tech. subjects like OOPS, TAC & OS till 5th semester. Secondly, instead of going for blind certifications on reputation basis will hardly develop your skills as software developer. You should rather go for any good coaching center for platform learning, like JAVA

U can go for Sun Certification/ Microsoft Certification courses