Talking to reporters, the IAF chief said the indigenous aircraft will have to be modified further for operating in high-altitude areas as recently during trials in Leh, its engine "did not work".
"By my estimate it (the Initial Operational Clearance II) should be by the end of this year and the Final Operational Clearance (FOC) should take another year-and-half more," he said on the sidelines of a seminar.
The FOC is the final nod required before an aircraft is considered to be ready for operational deployment in an air force. While the IOC I of the LCA Tejas was completed two years ago, but the FOC date has been postponed due to certain issues.
Browne said delays do take place in a development project such as the LCA. "Recently we went for high-altitude trials. The engine (of LCA) did not work at that altitude because it is a different cup of tea.
Even the Su-30, when it was taken to Leh, it had to be modified. So, the LCA will have to be modified. It has to do the retrials," he said.
The IAF chief said the aircraft will take part in the exercise 'Ironfist', which will be held at Pokharan in Rajasthan on February 22.
"There it will be firing the R-73 missile along with laser guided bombs etc. But a lot more work is still required," he said.
Earlier at an international seminar here, DRDO chief V K Saraswat said the LCA had completed 2,000 test flights.
At the same seminar, Browne said the IAF is planning to induct around 350-400 aircraft in the 12th Defence Plan period.
The air force is planning to procure more than 200 fighter aircraft including the 126 Rafale medium-multirole combat aircraft, over 40 Su-30MKIs, several types of transport aircraft and various choppers, he said.
Listing the major modernisation milestones achieved by the air force, he said the IAF signed 325 contract worth Rs 1.52 lakh crore for modernising the force.
"Of these, 217 contracts worth around Rs 84,000 crore have been signed with Indian companies," the IAF chief said.
In 2013-14, the IAF is planning to sign several deals including one for 126 Rafale aircraft, additional six C-130J Super Hercules and several chopper contracts for attack and heavy-lift category, he said.
On the future requirements of the force, he said advanced active electronically scanned array (AESA) radars, electronic warfare suites and unmanned combat aerial vehicles were the need of the force in the future.
The IAF chief said testing facilities of DRDO and defence PSUs should be opened up for private sector as they are national assets.