The eight fast breeder reactors which are outside the safeguard, can in principle supply the plutonium for the weapon program, but by doing so those fast breeder reactors will be unviable. The remaining all the power plants which will come under IAEA safeguard will not be able to provide plutonium to the weapon program. Thus this aggrement will practically bring an end to the weaponisation program. I can imagine two possibilities, one, there must be a closed-door agreement between India and US, that US will give future protection against China, something like Japan, second India has already achieved enough Nuclear warheads, as a credible deterence, or may be a mixture of both. However, the fact still remains India officially is still a non-nuclear country.
