@akshyasamjpath you will have to get the exact numbers of the main board. Then use those numbers and do an online search. See if it is available. I am certain there will be some used ones, but I do not believe you can get a new one.
If not, then you can try to find a complete BD-F7500 that may have failed with other issues then the motherboard. You could use that as a donor machine and harvest the motherboard from that. [guide|99523|Samsung BD-F7500 Blu-ray Player Mother Board Replacement - iFixit Repair Guide|new_window=true]
You have not told us why you need to replace the motherboard. Maybe there is chance of repairing yours.