How likely is it for gliese 581c to contain life?

Answer - it's possible but unlikely.

Scientists now think that Gliese 581c is slightly too close to its star; however they now believe Gliese 581d is in the "Goldilocks zone" and could support life. The only way to know for sure is to send a probe using matter antimatter annihilation. It would only take 30 years to go the 20.5 light year journey because of these speeds time dilation would come in so if it was a manned mission to the crew it would only seem like 6 years the spacecraft would have to be the size of a nuclear attack submarine manned or unmanned so by my estimates maybe by 2050 they will launch a probe there although i doubt ill still be alive to see the first images or video of the surface because it would take another 20.5 years for the transmission to reach us and maybe that transmission will confirm there is life there or it will confirm there is not to fully tell though the probe must have mobile landers maybe a lighter than air probe.

We have no knowledge of any of the extrasolar planets of the Gliese 581 system. Gliese 581 is a red dwarf star, which would seem to lower the probability of any of the planets having "life as we know it", but of course, we can only guess about "life as we DON'T know it". I guess we'll have to launch a probe there and look; I'm not sure I'd run the risk of sending a crewed colony ship there, to a sun so different from our own.