"home", there's a population of 10 million people that is resource and knowledge rich and can be tapped for a cause!
In fact after the 2001 Gujarat earthquake when President Clinton asked Prime Minister Vajpayee how he could help, the PM asked the President to mobilize the Indian-American population. Clinton then helped launch the American India Foundation(AIF). This organization later raised millions of dollars for the earthquake victims.
If the government is balking at the very idea of the Mig-21 replacement program because of financing issues, there is no reason why this population can not be tapped through a bond issue. It does not have to be charity, it could be a cess on resident Indian's tax bills, or it could be a bond for NRIs.
Assuming a reasonable coupon rate of 8-10%, and further assuming a face value of USD 1000, the NRIs of the world can help finance the entire purchase of 126 generation four fighter aircraft! The government can then repaay the money with the increasing tax revenues from a booming economy.