sir, recently i saw some islamic websites stating that there is a prophecy about their prophet muhammed in hindu scriptures, similarly some christian websites stated that jesus was mentioned in the vedas as saviour? which one of them is true? or both of them were false?
Both of them are false. However, Mohammad and many others are mentioned in a corrupted 'Bhavishya Purana'. Here is the relevant comment from Wikipedia:
"Hazra has the following to say regarding the Pratisargaparvan:
The Pratisargaparvan, though nominally mentioned in the Bhaviṣya (I.1.2–3), contains stories about Adam, Noah, Yākuta, Taimurlong, Nadir Shah, Akbar (the emperor of Delhi), Jayacandra, ... and many others. It even knows the British rule in India and names Calcutta and the Parliament.
A. K. Ramanujan mentions finding references to Christ (as Isha Putra), Moses, and Queen Victoria in the "appropriately up-to-date Bhaviṣya Purāṇa"and cites this as an example of the fact that:
"In spite of repeated efforts to impose schemes and canons on them from time to time, Purāṇas are open systems." http://en.wikipedia.org/wiki/Bhavishya_Purana#Comments
These are later additions. With best regards,