Abinash, each Degree has an extension period by 2-3 years which means, though you have registered for B.Tech in 204, your candidature holds good until 2-3 years depending on the University that your College is affiliated to. You can certainly give all the pending papers at a go and complete your Graduation. But you need to check with your College if your Candidature is still open because if you have joined in 2014, technically you should be on the college rolls to continue with the exams. Please reach out to your college.