all national fund contributions are eligible for 100% deductions whereas for NGO charities it is 50% deduction under sec 80G .... Uttarakhand relief fund would come under 100% deduction....
below are those which come under 50% deduction Jawaharlal Nehru Memorial Fund Prime Minister's Drought Relief Fund National Children's Fund Indira Gandhi Memorial Trust Rajiv Gandhi Foundation Donations to govt./ local authority for charitable purposes (excluding family planning) Authority/ corporation having income exempt under erstwhile section or u/s 10(26BB) Donations for repair/ renovation of notified places of worship World Vision India Udavum Karangal