Firepower onboard INS Sumedha. Oto 76/62 forward. Two NSV machine guns on the bridge with gun shield of one more.
https://pbs.twimg.com/media/Dc198RbUQAAxlgK.jpg
In the rear AK-630 and gun shield of one more NSV
https://pbs.twimg.com/media/Dc19-o6VAAAzklq.jpg
An MMG in the rear gun shield
https://pbs.twimg.com/media/Db2KGV5WAAElrnw.jpg
A whopping total of 8 HMG/MMG, two AK-630, one OTO 76/62 along with other systems like Carl Gustaf & LMGs will enable it take out a whole Somali pirate harbour. INS Sumedha is presently on joint patrol off Maldives. Can single handedly establish law and order in the archipelago if required.
In the meantime, INS Sahyadri, INS Kamorta and INS Shakti are patrolling Straits of Malacca in the event the PLAN try to interfere at Maldives.
This is how Naval Diplomacy works.
INS Sahyadri firing supersonic Klub S missile with a range of 220 km
https://pbs.twimg.com/media/Db2XtGYW0AA9Mu8.jpg
NSV manufactured for T-72 and T-90 tanks but adapted for naval use. Similarly 2A42 for BMP-2 is also adapted for naval use.
The many ways of controlling weapons.
On Type 17 - Barak 1, OTO 76/62 and AK-630 are controlled using Elta 2221 STGR
https://pbs.twimg.com/media/Db2XnfXWsAATrBt.jpg
On Type 28 - OTO 76/62 and AK-630 are controlled using BEL Shikari / Contraves Oerlikon TMX
https://pbs.twimg.com/media/Dcg3hbeXcAAqket.jpg
On Deepak class AK-630 are controlled using BEL/Elbit Compass EO
https://pbs.twimg.com/media/Dcg3gCTXkAAEUrb.jpg
The same systems can be used for land based AA, viz, AK-630, 2A42, L70, ZSU-23-4 & ZU-23-2 guns coupled with Flycatcher/Atulya and/or Compass EO with no need of imports.
Compass EO is the same CCD Day Camera, FLIR, LRF and LD as Litening Pods on Su-30, Tejas, Mirage 2000 & Jaguar. Compass is used on IN Ships, Rudra, LCH and new NAMICA (two sights). The two sights on NAMICA can be replicated on Arjun.