@muzamil13935 if you have not setup your phone to connect to a computer via USB for file transfer, there is not much you can do to get your files. At this point you really have not much to loose. I Suggest you take a look at the motherboard to see if you can determine which part is for the backlight/LCD and try to repair it. Use this Nokia 206 2060 Rm 872, Rm 873 SM to work on it and here is Nokia 206 Dual Sim And 206 Rm 872 873 Service Schematics V1.0 and the boardview.
If you have any issues with that, take some good pictures of your board and post those with your questions. that way we can see what you see and hopefully help you further.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!