How to install ROM when bootloader is not unlocked? Accidentally, on stock recovery, I selected wipe data/factory reset which could have uninstalled the ROM on it. So, now my mobile is showing company logo only.

My mobile HTC Inspire A9192's bootloader has not been unlocked yet.

How to boot the mobile again ?

Every time I restart my phone, the data/ cache and system gets unmounted.
A factory reset doesn't wipe the ROM files, only the user data, so you can't have "uninstalled the ROM" that way.

Having a locked bootloader doesn't stop you flashing a ROM: it just limits you to official ROMs signed by the manufacturer (or possibly by the carrier). So even if you can't or don't want to unlock the bootloader, you can still flash the stock ROM in the usual way from the recovery, if you can obtain a backup of it.