Hi Akhil Bose,
I had developed a product (Railway Indicator) for one of my clients, many years ago using P89C51RD2HBP. Availability of this IC reduced, and we started getting P89C61X2. With a slight change in source code, he was happy for so many years.

Now Philips (NXP) has done it again, now P89C61X2 is not available here, and they are promoting P89V51RD2. Fine till here.

But, now we are getting P89V51RD2FN. Now this is a new IC to philips range. And obviously they are not supported by the old programmers.

Now, out of desperation, my client, programmed the P89V51RD2FN in a parallel programmer by selecting P89V51RD2. But he disabled the feature of "Device Signature Check". And it worked OK, and he is happy now.

Just see if you can disable the feature of "Device ID Check", in your parallel programmer, and program the P89V51RD2FN by selecting the IC as P89V51RD2. It might work. He is using a programmer from ucmicrosystems (ucFlash). But, be ready to sacrifice an IC if it does not work.