How to install Play Store on Jio Lyf LS 4005?
Looks like you have done so much. Seems like they have cut the server connection between Google PlayStore and they use their OS. Only possible thing for you to do is flash a custom rom. To do it,


install Clockworkmod or TWRP mod.
Find an appropriate Custom Rom made for your phone.
then install Gapps if they dont have it. 


all the best