Auto major Tata Motors today said it has achieved India sales of 4 million vehicles since its inception in 1954.The company sold its four-millionth vehicle in the domestic market on October 30, Tata Motors said in a release.Total sales of the company, including exports, had crossed the four-million mark earlier in March, the release said.Tata Motors sales had reached the 1-million mark in 1991-92, almost 37 years after its inception, and since has rolled out 3 million more vehicles, the release added.