She sang 'Maahi Ve' in 'Kal Ho Na Ho' under the name Sujata Bhattacharya. What name does she use for Tamil songs?

Madhushree. Actually Sujata Bhattacharya is her real name. She opted for Madhushree when she began her singing career but switched to Sujata Bhattacharya because of pressure from dad. Now she's decided once for all, that she will stick to Madhushree. Source: Screen.