NEW DELHI : Angry voters in India's financial capital of Mumbai turned to lawyers and social media on Friday to vent anger at election authorities, a day after thousands were reportedly unable to cast ballots due to irregularities in the voting lists.Mumbai voters were among the 180 million people who were registered to vote in the sixth phase of India's mammoth general election on Thursday, but many were unable to cast ballots when their names were not found on the electoral lists."I went to the booth and they could not find my name ... it was disappointing, we've all been building up to this," said Mumbai resident Govindraj Ethiraj, adding that up to 20 people at his polling station had the same problem. Ethiraj said he had voted at the booth in the last three elections without any problem.The problem also affected some well-known Mumbai residents including Deepak Parekh, chairman of HDFC, one of India's biggest mortgage lenders, he told media.India is halfway through the world's largest-ever election in which its 815 million registered voters will complete the polls over 10 stages on May 12. Results are due on May 16.H. S. Brahma, one of India's election commissioners, acknowledged that lack of coordination between authorities had led to some lapses and he promised to fix the problem before local elections due later this year. "We'll rectify them, whatever mistake we have seen. We really regret (it)," Brahma told Reuters.Brahma said he did not know how many people were affected. Media said thousands were unable to vote, but it was not possible to independently confirm the numbers.A Mumbai-based law firm planning to file a public interest litigation in court next week said it had received about 5,000 queries and 250 people had signed up to the litigation."A citizen has been deprived of his right to vote and consequently has the right for redressal," said Mohan Jayakar, a senior partner at the law firm, Jayakar and Partners.Having an identification card issued by the poll panel is not enough to vote in India and it is mandatory for voters to have their names on the electoral list of their constituency.Similar problems surfaced in Pune, a city in the western state of Maharashtra that went to polls on April 17.Electronic voting machines and heightened security have ended abuses that plagued polling until the 1990s. Despite the problems with voter lists, India's elections are largely seen as free and fair.