The U.S. is offering to sell India a special F-16 that can do supercruise. Thirty years ago, the manufacturer of the F-16 modified the design a bit, and created a version (F-16XL) that could supercruise. That means it could travel faster than the speed of sound ("supersonic", or about 1,000 kilometers an hour) without using the fuel guzzling afterburner. The concept was put aside, because it wasn't really worth the effort at the time. A decade later, when the F-22 and F-35 were in development, supercruise was reintroduced. Mostly this is about more powerful engines, and a shape that accommodates that sustained high speed. The F-16IN would also have phased array (AESA) radar, that is more reliable and powerful than conventional radar. The aircraft would also have a passive (heat seeking) "radar" and extensive electronic warfare gear built in. This would be the most powerful F-16 ever built, and certainly more capable than the models Pakistan is getting. That could lead to a situation where F-16s would be fighting F-16s.
All this is part of an effort to snag a competitive Indian contract for 126 high performance fighters. India is willing to pay up to $100 million, or more, per aircraft, and now the F-16IN is a contender. At least on paper. The F-35 is not being offered to India for this contract because the F-35 will not enter service in time (as laid down by the Indians.) Moreover, the F-16IN meets all the requirement of the Indian contract, and is competitive with the other contenders (the U.S. F-18E, the French Rafale, Eurofighter/Typhoon, Russian MiG-35 and Sweden's Gripen.)