Executives of the multinational online transportation network company Uber on Thursday met commerce & industry minister Nirmala Sitharaman and discussed the need for a start-up ecosystem in the country, especially in tier-2 cities.The meeting comes in the backdrop of a recent complaint by the Association of Radio Taxis to the commerce & industry ministry, finance ministry, the RBI and the Enforcement Directorate that taxi app firms are allegedly violating FDI norms.