Can Kaal Sarp Puja be done online at Trimbakeshwar?

Yes, partially. A registered pandit performs the full puja at Trimbakeshwar after taking your Sankalp (name, gotra, intent) via phone or video call. Photos and video are sent to you. The Kushavarta Kund snan cannot be done remotely as it requires physical presence. For fully documented remote puja, Prayag Pandits offers this at Prayagraj and Haridwar with video specifically for NRI families.