Panasonic tx65dx902b tv tnpa6200 power board issue

hello sir,my issue here is my power suply for my panasonic tv tx65dx902b,board no,tnpa6200.iam trying to repair the driver board only i came to understand that the upper transformer is not driving and the regulator ic is not good.my main problem is that the ic number 6c16506 is not obtainable from any semiconductor store i checked.please which available ic can i use to replace that one.thanks