The  birth of Lord Kalki

Lord Krishna will appear in the home of the most eminent brahmana of Sambhala village, the great soul Visnuyasa.

According to the scriptures kalki is the final avatar of Lord Vishnu of this chatur youga cycle. 

Lord Kali will appear at the end of this Kaliyuga which is about 432,000 years away.

By that time Dharma on Earth will have declined upto like 99% and there will be evilness most of everywhere on Earth