Hello.

As you said you'll be appearing for your board in the coming year,then let me tell you it won't be a problem in you appearing for NIFt exam. As per the eligibility criteria,any candidate who has either successfully completed +2 or 12th of are appearing for +2 or 12th, can appear for NIFt exam. Now, like you asked that you want to apply in the month of October, let  me inform you that you can only apply when they publish the notification and start accepting applications. Till then focus on your 12th and NIFt preparation,all the very best.