India is not a NPT state ie. a state that has not signed the Nuclear Non-Proliferation Treaty. The Indo-US Nuclear deal is about the nuclear fuel and reactor transfer from US to India. Since India is not a signatory to NPT, the US Atomic Energy Act, 1954 stipulate a mandatory deal with IAEA and also with the NSG. The US Congress is voting the Indo-US Nuke deal. Once India sign the treaty with IAEA and NSG there is no problem in getting fuel from other countries. After getting the IAEA deal through and get the NSG countries to agree to give us the fuel, then we can even ignore US.