SKK, 29 Oct 2015what is operating systemI replied to your comment I hope what I said is helpful. :)
I am pretty sure this phone runs on a version of Nokia's old Symbian OS. Quite possibly Symbian S30/40. I just bought an Akai JEP-1215 Dual Sim Phone yesterday and it is almost identical to this phone apart from the battery being 600mAh.