The tender was issued in August 2007 and India is set to enter into cost negotiations in a couple weeks, after which a vendor will be chosen out of the six bidders, likely by September.
Planes in the running are the F/A-18E/F Super Hornet from Boeing, the Rafale by French firm Dassault, the Eurofighter Typhoon from Europe's EADS, Lockheed Martin's F-16, the Russian-made MiG-35 and the Gripen from Swedish firm Saab.
However, the head of the air force fears one or more of the losing bidders might question the procurement process, meaning an investigation would be started, which would probably delay the purchase and eventual induction of the aircraft into the air force.
"But some dissatisfied vendor among those not chosen for cost negotiations may put a spoke in the wheel and derail the process by going to the central vigilance commissioner with complaints leading to a delay, though we want to quickly sign the contract," Air Chief Marshal P.V. Naik told a news conference during the Aero India air show at the Yelahanka air base near Bangalore.
Defense Minister A.K. Antony reassured the news conference that the procurement process is and will be free from political interference and the winner would be chosen on the plane's capabilities and merits alone, as analyzed by the Defense Ministry.
This year's Aero India show is the largest, with 29 participating countries showcasing 93 fighters, trainers, private jets, helicopters and commercial jets.
Hindustan Aeronautics, which had headquarters in Bangalore, announced a 10-year plant modernization program and hinted that the company might go public.
HAL has 19 production divisions along with 10 research and development centers in the country and aims to design, develop and manufacture 1,500 helicopters over the next decade.
At the Aero Indian show, HAL Finance Director D. Shivamurthi said going public would make the company "do better" and be "much more responsive."
HAL also is set to upgrade 63 of the Indian air force's 69 MiG-29 fighter aircraft as part of $900 million deal with Russia's MiG Corp. The first six upgrades -- separate from the upgrades to be done by HAL -- will be done by MiG in Russia.
MiG is replacing the N-109 radar with a Phazotron Zhuk-M system. The aircraft also are being equipped for enhance beyond-visual-range combat ability and for air-to-air refueling.
The first upgraded aircraft recently had a test flight in Russia.