This is the fourth attack on Indians in the last two months.
Earlier three incidents were fatal.
"Police called at 08.23 on Friday, 10 February to Newham General Hospital after a man in his 20's was admitted suffering from stab wounds. He is currently in hospital in a critical condition," Scotland Yard told PTI.
"Officers believe the man sustained his injuries at an address in Kent Street, E13. Eleven people have been arrested. Four remain in custody. The other seven have been bailed until future dates. Detectives from Newham Borough are investigating," it added.
Indian External Affairs Minister S M Krishna spoke to the acting High Commissioner Rajesh Prasad, asking him to extend all possible help to him.
Krishna also spoke to Andhra Pradesh-based businessman Sudhakar Reddy, father of the stabbed student, Praveen, assuring him of all help in getting visa, official sources in New Delhi said.
They also said that High Commission officials in the UK were coordinating with the doctors treating Praveen and MEA officials in Delhi will take up the matter with the British High Commission to ensure expeditious issuance of the visa to his parents.
In the earlier incidents, 23-year-old Anuj Bidve was shot dead in Greater Manchester in Salford on December 26. The UK Police also confirmed on January 10, the death of 20-year-old student Gurdeep Hayer in Manchester city centre.
This was followed by the murder of Avatar Singh Kolar, 62, and his British wife Carole Kolar, 58, in Birmingham on January 11.