My Surname is Yadav and my gotra is Gargeya . Is that possible because Gargeya are Suryavanshi lineage and Yadav are Chandravanshi lineage. I am confused. I am from Maharashtra if it helps.
Well as you can see from the screen shot below & here that Bhuvamanyu (भुवमन्यु).— A son of Vitatha, and father of four powerful sons, Bṛhadkṣatra and three others including Garga, was the successor of King Bharata who was a Chandravanshi.
According to the Mahābhārata (Adi Parva), Bharata was the son of King Dushyanta and Shakuntala and thus a descendant of the Lunar dynasty of the Kshatriya Varna.
But I found another definition that matches the gotra you are seeking:
Gārgya (गार्ग्य):—Son of Śini (son of Garga). Although Gārgya was a kṣatriya, there came from him a generation of brahmaṇas. (see Bhāgavata Purāṇa 9.21.19-20)
So Garga are from Chandravanshi lineage.