Chieftain 2014 oil

Any help please I live in Istanbul Turkey there is no İndian dealer no service and every time I need oil change I don’t know what I should choose everybody had different opinions some says to use liquimoly semi synthetic 20W50 some says to use fully synthetic 10W60 .. for your information there are very few oil brands available in Turkey like (motul,Liqui Moly, Castrol,..) No amaoil No champion .
Thank you for your help