Super dependent on map but super generally speakibg you should have a

Hard Breacher - 99.99% on maps other than Coastline you will need a hard breacher, most of the time they drone in the entry, plant the defuser or hold flank.

Gadget Denial - a Twitch/Thatcher/IQ/Maverick that primarily assists the hard breacher to do their job. Destroy Mute jammers, Bandit batteries, Jager ADS's, or identify Black Eye Cameras, Maestro Evil Eyes or Echo Yokais.

Soft Breacher - a good soft destructor can often open new opportunities or turn the tide of a round. Buck/Sledge/Ash/Zofia or anybody with breaches will do.

Entry/Roam Clear - the early stage of a round involves attaining map control, hard breachers and gadget denial can't do anything if they don't reach the site. More dependent on the player and their comfort pick, it can range from Ash/Jackal/Blitz.

Special Utility - either for planting or map clearing, operators like Dokkaebi/Lion/Nomad/Capitao are solid picks. More often than not if smokes aren't being brought then this operator should bring them.

Keep in mind that this is super general and rather your team composition should be based on map/site.