Gujarat is the correct choice.
The Clinton Foundation, through its climate initiative wing, partnered with the Gujarat state government to develop plans for an enormous solar power park, targeted at a capacity somewhere between 3,000 and 5,000 MW. This announcement came around the time Gujarat was already emerging as a leader in Indian solar policy, later reflected in projects such as the Charanka Solar Park in the Patan region.
The reasons Gujarat was picked over other states include its vast tracts of dry, sun soaked land unsuitable for farming but ideal for solar panels, and a state administration that was actively courting renewable energy investment at the time. None of the other listed states, Bihar, Orissa, or Rajasthan, were the site of this specific Clinton Foundation project, though Rajasthan would go on to build significant solar capacity of its own in later years.
Therefore, the state where the Clinton Foundation firmed up plans for this world scale solar park was Gujarat.