"We will bring the Janlokpal bill in 15 days and a corruption-free India within six months," Kejriwal promised.
He attacked the government's economic policies.
"Inflation has not gone upward by itself. The government is imposing taxes which leads to increase in the prices of diesel and petrol," he said.
Kejriwal's colleague Manish Sisodia, who declared the name of the party to the gathering at Parliament Street near Jantar Mantar in central Delhi, said: "It is our party."