When I check my motherboard details, it always shows that "To be filled by O.E.M". It doesn't shows any model
My question is there any problem in installing a GPU cuz I see people telling that the motherboard BIOS is locked so....
Motherboard BIOS being 'locked' can mean any number of things. What are the rest of your system spec's?
Motherboards we buy 'off the shelf', in retail packaging, are also sold in lot quantities to system builders. Pre-built system mfr's will put branding and serial number information in a secure location provided for the purpose to identify their product for warranty and other purposes. When sold retail, those spaces are left blank or with that notice..."To be filled by O.E.M".
A VAR might just take retail parts off the shelf to put together a pre-built system to sell, so those fields would likely remain unfilled. There aren't many VAR's (Value Added Retailer) in the US today since American consumers tend to align with product branding above actual performance.
And Amazon has pretty much killed off the 'computer show', where you'd pick out parts like vegetables at the market and they'd throw it together as you watched. No careful cable management, no time.