Attending walk-ins is your best bet along with uploading your resume to all the popular job portals.
But even before that, you will have to have a solid command over the basic math and reasoning skills along with your graduation topics. So when you get the next opportunity, you grab it.
start up your own business.
I object seriously. Never start a business because you can't get placed through campus placement. It would seriously turn against you if you are not passionate about entrepreneurship. Instead, keep looking for jobs - because there are plenty of them.
One of my friends, took up a teaching job with a local computer institute and worked there for about 1.5 years. He then applied for jobs - and guess what, he exceeded all interviewers' expectations.
I'd also advise you to look for jobs with startups. If you can prove them that you have the right technical knowledge, they'll be happy to offer you a job. Your struggle is limited to entering into IT and no matter which door you take, you can always look for better perspectives in an year or two.
If everything fails, opt for higher education, you will spend about two years learning more and then your prospects for better job go up.
I hope this helps. Ask if you have more questions.
PS: Keep watch on CE. Our members keep on posting information about latest walk-ins.