I had a friend in girl, she was very friendly, we watched movies together, she found me very attractive,she favored me many clues that she liked me but we were from different cultures so I couldn't able to understand . And then about 3-4 weeks ago she suddenly started ignoring me.when I asked her the reason she didn't reply at all. And then after 2-3 days my best friends told me that they seen this girl with another guy in a mall hanging out together , that incident pissed me off and I felt very bad, and I said many nonsense crap like things to her and she told me that the guy was just her friend and then she told me to never talk to her again. I apologized for my rude behavior that day and also offered her to be just formal friends.I haven't got any text for at least 3 weeks, then she suddenly sent me a text "heyya , wssup ?? how's study goin on??blah blah blah..." I replied "hey , i'm fine and ya my exams will be after 3 months".. then I haven't got any reply that day.. but yesterday she txted me"i meant to send that msg to some other person, sorry wrong txt to you...." I mean godd what's this? I think other guys of her batch in college would probably told her many bad things about me,because I think I'm good looking then them and that made them jealous about me.. is she still likes me ? Hitting the gym will helpful to me ? Or should I apply no contact rule for at least 2-3 months according to my condition?give me your opinions, your help will be appreciated guys.. sorry for terrible english :P

Apply no contact rule for the rest of your life, and move on. You can't get something back that you never had. Liking each other does not make a relationship, at least not a romantic one. You missed your shot, move on.