kullananlarda
kullananlarda is a Turkish word that translates to "in those who use" or "among users." It is a possessive suffix used to indicate that something belongs to or is experienced by a group of people who are utilizing something. The suffix "-larda" is attached to a noun or pronoun to denote this plurality and possession.
For example, if one were to discuss the effects of a particular software, "yazılımı kullananlarda" would mean