What do the letters ly mean on the inside of gold ring?

They are the assay marks made by the jeweller which indicate the quality of the gold (eg. 9, 18 or 22 karat) and the origin. Where to sell? I have successfully sold jewellry on Ebay and most jewellers will give you an insurance value so you can set a reserve price.

the numbers are usualy how many carrots it is and the letters usualy mean what styl or wear i came from

take it to a gold dealer any ware that sells gold and they can price it for you buy reading the numbers letters and weıging it