As you want to join Indian navy and for the same asking for Indian navy's Elite Marine Commandos Marcos, so here is require info:

MARCOS, also knows as Marine Commando Force (MCF), is the special forces unit of the Indian Navy, MARCOS are known to be very secretive, not revealing their actual identity as specialised, elite soldiers. In their operations, they are sometimes assisted by Westland WS-61 Sea King transport helicopters, Chetak helicopters and two-man submarines. MARCOS can be launched from ships, aircraft and submarines in full battle gear.

Indian navy's Elite Marine Commandos Marcos info:
Type Special Operations Forces
Role

Primary tasks:

Amphibious warfare
Counter-terrorism
Direct action
Special reconnaissance
Unconventional warfare
Personnel recovery
Combat search and rescue
Asymmetric warfare
Counterproliferation
Underwater demolition, reconnaissance, seaborne infiltration and exfiltration
Hostage Rescue
Foreign internal defence

Other roles:

Amphibious reconnaissance
Hydrographic reconnaissance

Size Classified
Regimental Centre Mumbai, Visakhapatnam, Goa, Kochi and Port Blair.
Nickname(s) Magarmach (Crocodiles)
Motto(s) "The few the fearless"
Anniversaries 14 February.
Engagements Operation Cactus,
Operation Leech,
Operation Pawan,
Kargil War,
Operation Black Tornado,
Operation Cyclone,
Counter-terrorist operation in Kashmir.