If soraka dies in battlefield with 6 recruit how many rexruit save?

Yes — all six. Soraka's save is a replacement effect, and Rule 370.4 says a permanent can apply its replacement effects to any qualifying events that occur simultaneously with it leaving the board. So even though she's dying at the same time, she still sees every 1 Might Recruit at her location and replaces each death separately (Rule 373.2 — one sequence may cover any number of qualifying events).

Each saved Recruit is instead healed, exhausted, and recalled to Base, so they leave the battlefield intact but don't stay there. Note this also works when the deaths come from simultaneous combat damage — the older answers saying she can't save units she dies alongside were superseded by the 2026 replacement-effects clarification that Rule 370.4 codifies.

One caveat: they only get saved if they'd actually die and each has less Might than her printed 4 — a Recruit buffed to 4+ Might wouldn't qualify. And because the deaths are replaced entirely, they never count as "dying" for Deathknell or "when a unit dies" triggers.