I passed my 12th Board exam in 2013. I want to repeat 12th again. Will CBSE allow me to give 12th Board again in 2015?

I've pursued higher studies (just a year : 2013-14) in an engineering college. I gave entrance exam (JEE.Main-2014) but couldn't score well. I want admission in better college. Getting a TC from college means payment of 4-year fees which i cannot afford. Only chance: give 12th Board+JEE.Main-2015 !