Culprit is lg hd ready tv i even i got the same tv with same problem on punjabi regional channels whether siticable earlier or tata sky hd box now. While 40” grey market samsung tv is showing better picture quality in both boxes.
Bro..I thought the same way after checking the TV with my friend's local cable HD box for similar pq but after I calibrated the tv there was significant change in pq on the local box and nothing much in my d2h.
In fact I'm forced to reduce the sharpness to almost zero 4 nullifying the pixelated frames in some sd channels in d2h
Thank you guys for your time
I think I got my answers.
Infact a new HEVC Airtel box and an old ts hd box in two of my colleagues' houses forced me to this post, as @Vadirocks bro said,Personally I think new airtel HEVC is par with old TS HD for sd Pq in some channels.
As both of my colleagues use similar TVs of different made I can't trust it will be same in my lg and I'm unable to check it with my TV as they live far.
once again thank you all