Microsoft announced that it was dropping over $7 billion to purchase the Devices and Services arm of Nokia back in September of last year. The deal required the approval of regulators in the US, Europe and Asia before it could close.
Nokia originally expected the deal to close in Q1 2014. If you are paying attention this is the last month of Q1 and now Nokia is saying that the deal won't close until next month. Nokia is predicting that the final approvals will come and the deal will close in April.
Nokia and Microsoft are both committed to the deal despite the delays. The required regulatory approvals in the US and Europe have been received. The delay is because the Asian approvals haven't come in.
Nokia says that certain antitrust authorities in Asia are still conducting reviews. Nokia also says that the delay in the deal closing has nothing to do with tax proceedings in India.