While S550 is in the planning stage, the S-500 system is still pending induction after successful trials.
Sources said detailed discussion over S500 and S550 would be carried out during Russian President Vladimir Putin's visit to India in December this year.
Dmitriy Shugaev, Director of the Federal Service for Military-Technical Cooperation, would be overlooking the entire strategic mission of sale of the new anti-air defence system. He is also considered to be the putative heir to Rostec State Corp chief Sergey Chemezov.
"But all eyes are on what would be on the negotiation table," the source said.
ALSO READ | China launches compulsory recruitment drive for locals in Chumbi Valle
Also during Putin's visit, Russia will deliver the first lot of S-400 anti-aircraft missile system.
India had procured the S-400 system from Russia in 2018 for $5.2 billion. Russia will deliver the first lot in December this year. It will be the main pillar of the Indian Air Force's defence grid.
Earlier this week in Moscow, Russian Defence Minister Sergei Shoigu had announced that Russia is developing an advanced, never-before-seen S-550 missile system. He, however, did not give details about the design or capability of the system.
"The head of state placed special emphasis on the importance of advancing the development of domestic air and missile defense systems, and the supply of S-350, S-500 and S-550 to the armed forces," Shoigu had said at a Defense Ministry conference in Moscow.
The Russian state news agency TASS said that the erstwhile Soviet Union had been developing the S-550 high-mobility terminal air defense system in the 1980s. The project, along with many others, was closed as part of the Soviet-US military agreements of that period.
ALSO READ | EU delegation visits Taiwan
The equipment installed on the system's prototype was dismantled after 1992. The project's groundwork was destroyed after the collapse of the Soviet Union, it stated.
The latest S-500 system is still pending induction after successful trials. Now, the Russian Army will get the first batch of S-500s. Earlier, the Russian Army had stated that it would receive the first S-500 systems in 2020.