Yes, you can apply for JEE Main as a PCB student and aspiring candidates of NEET There is no illegal issue in appearing as many candidates before have done it and there is no such rules that you cant give exam but remember that You will be considered ineligible for JOSAA counseling. However dont waste your precious time, energy and money in appearing such exam which is of no use for you instead go for mock tests where you also get to know your performance.

Prepare for NEET, AIIMS & JIPMER if you are medical aspirant or focus on board if you want to do general courses where entrance exam required at college level If you want to feel like real exam go for test series of any coaching centre.