I with other families have been to Bangkok in November, 2011. we were looking for some north Indian restaurant there and by coincident ( hotel we stayed nearby did not mention it), we find this bhagat tarachand restaurant on main road near Ashoka metro station there. we decided to try it out and lo that has been a great experience with really great north Indian food with friendly staff. Food there customized as per your need. I recommend it if some is really for some authentic Indian food and you will not be disappointed.
Satishh