Richard Biener shared the latest GCC 6.3 status report with an aim of seeing GCC 6.3.0 officially out by Christmas, or later this month. The code is down to zero P1 regressions (the highest priority bugs) but there are 199 P1 through P3 regressions. Richard is planning to cut the GCC 6.3 Release Candidate next week, but until then it's still open for documentation and bug fixes.
More details via the GCC mailing list. For those looking towards the next big feature release, that's GCC 7 and will be released as GCC 7.1 in H1'2017, having entered stage three development just recently.