The prediction that Lord Kalki will be born in the town of Shambala near the end of Kali-yuga from a brahmana who is actually an incarnation of Svayambhuva Manu. It is described that Svayambhuva Manu performed austerities at Naimisaranya on the bank of the Gomati River for acquiring the privilege of having Lord Vishnu as his son in three lifetimes. Lord Vishnu, being pleased with Svayambhuva Manu , granted the blessing that He would appear as Svayambhuva Manu ‘s son as Lord Rama, Krishna, and Kalki.
Thus, Svayambhuva Manu would appear as Dasaratha, Vasudeva, and then Vishnuyasha. Padma Purana 1;40:46 also prophesied – Lord Vishnu admits that He will be born in Kali-yuga. (Sankshipta Padmapuran, Chapter – Utterkhand, Title – “Ramavatar Katha Description of Birth ” Page No 949)