Singh said his mother Nirmal, 76, was in intensive care in Chandigarh after falling in her garden, according to Reuters.
'She has fractured her knee and the fibula bone and needs major surgery,' Singh told reporters.
'She needs some plates put in and that surgery is going to take place tomorrow morning. We are hoping and praying that everything goes fine and she comes out well.
Singh's mother can take some credit for his athleticism. She used to be a national-level volleyball player and still plays golf.
Singh's 64 came a day after Sergio Garcia also shot a 64 to tie the Greg Norman-designed Earth Course mark held by Britons Lee Westwood and Ross Fisher, Swede Peter Hanson, Martin Kaymer of Germany and last year's tournament winner, Alvaro Quiros of Spain.
Singh equaled the record despite playing with a finger injury.
'I would like to take some time off but these tournaments are so good that I can't stay away,' he said.
'I can't really hit the shots I want to hit, especially the punch shots, because it really hurts when I dig into the ground. The putter was really hot today and I think that was the reason for the 64.
'The doctors told me to take four months off but that's not in my dictionary. I love this game too much.'