It's perfectly fine to go for Paragliding in Bir-Billing in March. Just remember not to take an early morning flight if you are opting in for video recording too as you won't be able to shoot a good video as the sun will be just above you at that time.
March is the month in which snow starts to melt in Himachal, it will be a nice place and nice time as well.
for Paragliding @Bir Billing it will cost 1500rs and 2000rs with Go Pro.
October to June is the season for paragliding. Even October – November and March – June are the best time for long flights. Paragliding experience during December, January is different as all the mountains around covered with snow, even Billing experience snowfall during that period. check out the link below.
http://www.travelbirbilling.com/tours/paragliding-in-bir-billing/