Be specific and I suggest you to post this query under 'Ask Experts' section. You will get good advice there by ISC experts.
As you are new to ISC, I feel just go through its help section to get a feel of this site.
Knowledge is power.
There are many competitive examinations. The eligibility criteria will change from exam to exam. If you are an Engineering graduate you have a different competitive examination. Of course, some are common. So to have a precise list useful to you, we require what is your qualification and what type of job you are looking for. Then we can suggest and give you the list of competitive examinations which will be suitable and useful for you.
I wish you all the best and I hope you will have a good time on this site which is a very site for learning and side by side for earning also.