Yes, you can appear for JEE (Mains) & JEE (Advanced) 2014. The exam pattern for IIT JEE has changed from 2013. You need to score above 80% to be eligible to appear for the IIT JEE (mains) entrance exam. Basis this score, you can apply to NIT’s and centre & state funded engineering colleges in India. If you want to get into the IIT’s, you will need to appear for JEE (Advanced) exam.
There are various articles on the changes in JEE Main and Advanced Test. You can get these articles by clicking here