Hello Kanwar
How are you?
All touch screen phone screens are made up of third parts
# Glass
# Digitiser
# Screen (LCD or OLED)
Most phones screens fuse all three of the above together making it almost impossible to separate without damaging the screen. Most phone repair places don't even try as the amount of time needed out ways the cost to charge the customer for a full screen (all three of the above parts) Assembly.
LCD screens are much cheaper than OLED
I can find a full Screen Assembly for Xiaomi Redmi 2 for only AU$23.43
Hope this helps