TLDR; If you defrosted the chicken in the fridge, go ahead and refreeze it. If you thawed it on the counter, cook it, then freeze it.
I was always taught: DO NOT REFREEZE uncooked meat!
But, I did a search and found this somewhat contradictory statement from a reliable source:
Once food is thawed in the refrigerator, it is safe to refreeze it without cooking, although there may be a loss of quality due to the moisture lost through thawing. After cooking raw foods which were previously frozen, it is safe to freeze the cooked foods. If previously cooked foods are thawed in the refrigerator, you may refreeze the unused portion. Freeze leftovers within 3-4 days. Do not refreeze any foods left outside the refrigerator longer than 2 hours; 1 hour in temperatures above 90 °F.
If you purchase previously frozen meat, poultry or fish at a retail store, you can refreeze if it has been handled properly."
There's also this: How long will uncooked chicken keep in the fridge?
Which says 1-2 days for raw chicken in the fridge.