Vikram Mookerjee was a fake alias created by Ross so Phoebe's new love interest, Mike, wouldn't think she had never been in a long term relationship. [[[The One With The Sharks]]]
According to both Ross and Phoebe's lies, Vikram is a kite designer with whom Phoebe had been in a six year relationship with. Vikram apparently had a glue sniffing addiction.
Ross had called Phoebe and pretended to be Vikram as his message played on the answer machine. Prior to this, Phoebe admitted to Mike that there was in fact no Vikram.