Hi aspirant,

basic education qualification required for appearing in JEE main, one should completed 12th or appearing in 12th. Also there is no age limit in appearing in JEE main. In your case you already passed 12th so you can appear for JEE main and no need to pass 12 again. However you are still going to appear for 12 again, then also you can appear for JEE main.

hope this is helpful to clear your dilemma.