NEW DELHI- Qatar has reassured India that labour reforms will improve the conditions of more than half a million Indian migrants, after Prime Minister Narendra Modi raised concerns of abuses during a weekend visit to the Gulf state, a statement said on Monday. Qatar is home to 630,000 Indian nationals, the single largest group of migrants in the country of 2 million. Many work in low paid construction jobs, building stadiums and other infrastructure for the 2022 World Cup. Rights groups accuse Qatar of abusive labour laws and forcing migrants to work under poor safety conditions. Unions and labour protests are banned, and authorities penalise dissent with jail or deportation.