i no longer have a bsnl connection at my place here in gurgaon so cannot test with you.
both dailymotion and
mega opens for me on reliance broadband with
google public
dns.
bsnl customer support is unlikely to be of any help regarding random blocks on online services.
you can try complaining through the
pgportal. it should work better with bsnl compared to reliance for me.
if you have an option for a different ISP, get it. otherwise, get a good quality
VPN service to continue with your work.