Suggest me some good low end multiplayer preferably FPS games.

https://www.lorenzostanco.com/lab/steam/u/shantanuthakur_DX24

Use filter FPS, multiplayer

I believe all games will work fine on your pc (except h1z1 and Quake Champions)

Killing Floor

Serious Sam games. The non-HD version of Painkiller and its first expansion (but not the others).
Unreal Tournament '99, 2k4, probably even III.

Team Fortress 2.

Some of the F.E.A.R games?

https://www.systemrequirementslab.com/cyri

Insurgency?, seems you have it already, why not try it?

Stick Fight is fun but not for the long term xD

https://store.steampowered.com/app/296300/Ballistic_Overkill/

Try Warframe. Haven't played it, but I'm planning to try it.

Does stardew valley count?
Just started multiplayer recently so you can play with close friends or others on stardew discord/Reddit/steam group.

Or don't starve together.

Doom, wolfenstein series (at least the older games) will run fine on your system.

What kind of videocard we're talking about?

I had a pc with similar specs in the past(it sucks) so here's a list of some of the games I played:

• CS Source
• GMod
• Fistful of Frags. This game is very.... Unique. It's slow paced, but at the same time really fast. It has a very unique gameplay overall. But that is what makes the an unique experience. It's among my favorite games(and one of the most played) and heck it, it's free.
  It receives regular updates which is nice and the community is basically a bunch of drunk people asking for whiskey. It's a thing in the game, you'll see Pass the whiskey
• Left4Dead2 should run fine. Might want to tweak a little here and there, but just for minor things, no need to worry too much about it. It's fun, kill zombies and stuff. Mods(although I never played mods on L4d2, but it's a big thing). Tanks are always nice to remind you that you actually have to think a little
• Killing Floor. Yes, a lot of people migrated to the second floor, but there are still people playing it.
• The Hidden mod. It's a source mod. It is fun with friends. It can destroy friendships, but those are details.
• Battlefield 2 mods. Honestly I don't know if they are still active or not. Search for forgotten hope 2 and project reality.

I'll update this comment if I remember any other. I had more but for some reason it got deleted and I had to write all over again :p

I suspect the first FEAR game would run on that, it's quite old (and no multiplayer AFAIK) but it's really good. Fanatical has a bundle of all of the FEAR games for a good price.

You could try out No More Room in Hell. It runs on the Source Engine. So if you can play Valve games this one should run as well. It is however rather slow and the focus is not on shooting stuff but on melee. Also graphics are dated and some animations look odd. It is still an interesting co-op game and different from other zombie games. And it is free.

If you try it out do yourself a favour and skip on the unlimited ammo servers as they completed ruin how they game should be played.

Insurgency.

    OS: Windows® 7
    Processor: Intel® Core™ 2 Duo E6600 or AMD Phenom™ X3 8750 processor or better
    Memory: 4 GB RAM
    Graphics: Video card must be 512 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 3.0
    Hard Drive: 10 GB HD space
    DirectX: 9.0c

Recommended
    Memory: 8 GB RAM
    Graphics: Video card 2048 MB or more
    Hard Drive: 10 GB HD space on a SSD

https://store.steampowered.com/app/222880/Insurgency/

The game is Source engine based, so gameplay is like counter strike. Community is friendly; voice chat is a mix of people audibly shitposting for giggles and tactical communication. Around 10 000 players at peak the laat time I saw the game's population chart last year.

Did you try Armello?It can run fine on low end pc.

borderland series