To apply for online counselling for B.Arch through JEE Main Paper 2, first register on the official JoSAA website using your JEE Main Paper 2 details. After logging in, fill in your preferred colleges and courses, then lock your choices before the deadline. JoSAA will allot seats based on your rank and preferences. If you get a seat, you must visit the college for document verification and fee payment. Keep your JEE scorecard, 12th marksheet, category certificate, photo ID, and photos ready.