Does neighbours witness is sufficient for adultery ?

It's been 1 year and 3 months for my marriage and My wife has been cheating me since before marriage. I did not come to know about her and Deepak's relation even after marriage. One Day I doubt her as she was on call with him in toilet and said him that I'm came early today and She will talk him tomorrow. I asked her she but She didn't tell me the truth and said she was listening ringtones in bathroom. So I decided to find out the truth and I got call details of her phone and I was shocked that She used to talk with that guy all the day and night (as I'm B.P.O. worker I have night Shift). She even ask Deepak to come at home without my presence and he came three times in night, My neighbour seen him at my house. I'm feeling like never before., I'm very sad as She went at her father's house and we are not talking to each other these days.I don't trust her now. Please suggest me what to do and what may I do in terms of Divorce ? Does it comes under Adultery ? or does she have rights to ask for maintenance or alimony to me ? What should I do ?