Context: 

Deliveries of five regiments of S­400 air defence systems under a $5.43 ­billion deal with Russia are expected to be completed by year ­end or early 2024, according to official sources. 

Image Source: The Indian Express

About the news:

• India has contracted five S­400 regiments under a $5.43 billion or ₹40,291 crore deal as per a conversation rate of ₹74.2 against the dollar at the time, signed in October 2018. 
• The deal has been delayed from the start over payment issues. 
• India and Russia have agreed to conduct payments through the rupee rouble arrangement after trying payments in euros as well.
• Delivery of the third S­400 regiment has been completed.
• The three regiments are deployed along the Northern, Eastern and western borders.

About the S-400 Triumf Missile System:

• The S-400 Triumf is a mobile, surface-to-air missile system (SAM) designed by Russia. 
• It is the most dangerous operationally deployed modern long-range SAM (MLR SAM) in the world, considered much ahead of the US-developed Terminal High Altitude Area Defence system (THAAD).
• The system can engage all types of aerial targets including aircraft, unmanned aerial vehicles (UAV) and ballistic and cruise missiles within the range of 400 km, at an altitude of up to 30 km.
• The system can track 100 airborne targets and engage six of them simultaneously.

News Source: The Hindu