Antony's warning was part of a general statement during his opening presentation to the 37th Directors Conference at the Defense Research and Development Organization.
Antony urged government-run agencies -- in particular the DRDO -- to speed up their work.
It was DRDO Chief V.K. Saraswat who set the date, he said, when the Tejas should pass final operational clearance for induction into the air force.
Antony praised the completed projects including the Agni-5 and the BrahMos missile systems as examples of good indigenous research and development.
But DRDO scientists should focus on priority areas where the ultimate test of success of the organization, its products and services lies in satisfaction of end-users, India's armed forces, he said.
"The successes shouldn't make us complacent and unfinished projects, which are in the pipeline for a very long time, should be concluded at the earliest," Antony said.
To achieve this, the DRDO remains essential for development of the country's defense manufacturing sector, he said.
"If our indigenization goals are to be realized, DRDO will have to take the lead in this regard," Antony said. "Other stakeholders, for instance the (military) services, the Ministry of Defense and private industry in the defense sector, must cooperate to ensure quick, honest and transparent acceptance of the systems."
The single-engine, single-pilot Tejas, being manufactured by Hindustan Aeronautics Ltd., was given the green light by the government in 1983 but it wasn't until 1988 that more concrete designs were on the drawing board.
Delays ensued, including issues over the design and performance of the intended Kaveri engine, a DRDO partnership deal with Snecma of France.
A Tejas prototype eventually flew for the first time in January 2001 -- but with a U.S.-made General Electric F-404 engine as a stop-gap.
A long-term deal with GE for 99 engines -- likely the upgraded 414 -- worth $800 million was signed this year because of further delays to development of the Kaveri engine. GE won over Eurojet's EJ-200 engine, a report by the Deccan Herald newspaper said.
Last month, the DRDO confirmed it had abandoned plans to jointly develop and produce the Kaveri military aircraft engine solely with Snecma, a report by AIN Online news said.
"We still need an overseas partner but it won't be Snecma on a single-vendor basis," C.P. Ramanarayanan, director of the DRDO's Gas Turbine Research Establishment, said. "We will select our partner through competitive bidding."