Stock OS or any other supporting OS for a rooted HTC rhyme S510b i rooted my HTC rhyme about a year before and installed MIUI OS of version 3.5.3 of android version 4.0.3. now i need my stock rom back what should i do?
You can download the stock ROM for HTC rhyme and flash it. Done!

This link seems to provide the 4.0.3 ROM to download and flash. You can also google to find other stock ROMs to download.