I'll help yeah ur rite Gautam first married Ganga then Teesha and finally Damini. Ganga first came into the Viranis lives as a teacher for Prajakta's daughters Sanwari and Banwari (Hansika used to play her). The Virani family found her to be very kind and generous. Tulsi thought she was the perfect match for Gautam as Gautam was very rowdy then she thought Ganga would change him. Mihir's brother's wife who was Aarti had taken Gautam away 20 years ago to Australia and raised him there (she had taken him away from Tulsi as she was very attached to him). Aarti found another perfect match for Gautam who was Teesha and as Gautam hadn't changed back then, he was still sided with evil Aarti (the Virani family did not know of Teesha or Gautam still being evil). Gautam did get married to Ganga on Tulsi's saying but secretly still kept his relationship with Teesha. As Gautam spent time with Teesha, Ganga felt alone most of the time (she didn't know about Teesha too) so Sahil gave her company. The too started to become friends and then slowly started falling in love. Also, a very famous face was introduced (guess who...KARAN!) as a business man but also a friend of Sahil and also tried his best to get them together. When Tulsi learned that Gautam did not love Ganga and Ganga did not love Gautam but loved Sahil, she tried her best to get Sahil and Ganga together. But, the family members went against her and were trying to stop her from doing so (mostly Savita and Pooja) but when they all learned that Gautam loves a girl named Teesha and was still on the side of Aarti, the family members started saying bad things about him (Baa even cursed them by saying that there marriage is not going to last for long) they were thrown out of the house. The family members apologized to Tulsi and happily got Ganga and Sahil together, while Gautam and Teesha lived with Aarti. This went on for quite a bit and a lot of times destiny brought Gautam and the family together. One of them being when Tarun (Sahil's younger brother who disappeared) and his friends kidnapped someone they thought that was called Khushi but actually it was Banwari and Gautam consoled Sanwari everything would be alrite and he tried to find Banwari. Tarun found out that the girl they had was actually his sister so he tried his best to get her out of there. Gautam slowly turned over a new leaf and eventually he was accepted back into the family where Ganga-Sahil and Gautam-Teesha got married together.
Hope that helped, btw this was quite sometime ago so if I made mistake, SOWWIE! 😳
If you want more info then dont be afraid to ask 😉