if a chicken has been in the freezer from November 18 till now July 2 is it safe to cook it and eat it?
Frozen foods will remain safe for a very long time, provided that they were treated with care before being frozen.  If your chicken was kept refrigerated before freezing and frozen before spoilage, or purchased frozen...AND, you thaw it in a safe manner (in the refrigerator is best), it will be safe to cook and eat. Freezer temperature matters, as does the temperature cycling that most home freezers do to maintain a "frost free" environment. This impacts quality, rather than safety. In the end, it is more likely that the quality has degraded, especially if it is not vacuum packaged.  A lot depends on the packaging.  There is a good chance that it has freezer burn (dehydration); with that comes the potential of off-flavors and textures.  However, that is not a safety issue.