The Income Tax Department has slapped 20,495 crore Rupees tax notice on Cairn India Ltd Friday. The notice was served for failing to deduct withholding tax on alleged capital gains made by its erstwhile promoter, Cairn Energy Plc. In its reply Cairn India said it does not agree with the tax demand and will pursue all possible options to protect its interest. Earlier this week, the I-T Department had slapped 10,247 crore rupees tax demand on Cairn Energy Plc for an alleged 24,500 crore rupees worth capital gains it made in 2006 while transferring all its India assets to a new company, Cairn India, and getting it listed on the stock exchanges. The company is latest to join a slew of multinational firms, including Vodafone and Royal Dutch Shell, to face tax demand owing to a retrospective tax law.