In Pune, there is one cable ISP http:\www.smjet.com, www.siliconmountains.co.in (Silicon Mountains) using cable internet.
In Pune a company Divinet (http://www.cdacindia.com/html/press/archives/otdn02/spot260.asp) (www.divinetaccess.com) is in the field of Cable network distribution devices.
Cable Internet is a huge business / Tech area. There are various kinds of details you might want - e.g. Network itself (Back End, Distribution, Client-end), security, performance - especially in Metro environment, effect of metro envioronment on the distribution networks, Network applications e.g. browsing, multimedia, VoD, video streaming etc. If you just take the network itself then these are some of the thins that would come in - MAN, RF-Cable based networks, Fiber to the Kerb or Hibrid Networks), Network Management and User Life Cycle management are some of the other areas.
Cable network equipment providers could be good resources.
Regards Vilas Wagle