Hi Arvind,
Yes, it is surely possible to fill the BArch form now, as GGSIPU offers different CET exams for different discipline like BTech, BSc, BA, etc.
So you have to fill a different form for each one you wish to apply and pay the amount for all the forms and then you can sit in the respective examinations.
You can fill the form once they are out which most probably get started around end of may or start of june.
Thank You.