For clothing:
* Col: This is the most common translation for "collar" when referring to the part of a shirt or blouse that fits around the neck.
* Collier: This word is usually used for a necklace or chain, but it can also be used for a collar in some contexts.
* Cravate: This refers to a necktie or cravat, but it can sometimes be used to refer to a collar, especially in formal contexts.
For other contexts:
* Collier: This can also be used for the collar of an animal, such as a dog or cat.
* Collet: This is a less common word that can be used for a collar, especially in technical contexts like engineering or jewelry making.
The best translation for "collar" in French will depend on the specific situation.