about police

Respected Sir, I am Shubham kumar and i am fronm jamshedpur,jharkhand.Sir,there is a park in my city and i always go there with my friends.Yesterday when I was sitting in the park at around 7:00 pm in the evening,two cops of the JHARKHAND POLICE came there and they suddenly started abusing me and one of my female friend.When i asked him that please answer me the things due to which he was abusing me but he didnt answered me and further started beating me and he also called my female friend as a "prostitude". Sir i also wan't to mention that in the park i was not doing anything which could be taken under the sence of VULGARITY. But now I have my clear plans. I want to go and appeal it to the court. Sir can you tell me that is it written in the indian constitution that any cop can abuse any citizen of India.And if you can also tell me that what are the procedures through which i can file case against that particular cop.And under which sections that cop is guilty of. And i also wanted to ask that in the park,in evening,if any couple is just sitting in the park without any vulgarity,can any policeman come and start abusing that couple. Is it correct ?but if the policemen still does so then can the couple challenge the policemen legally Sir plese tell me the charges under which i can sue that cop in the court.and please elaborate the process also. thank you Sir.