Buses not available between Carmelram and Electronic city. It is better to get down at Hosur and reach Electronic city. You can either take Bangalore bound mofussil buses from Hosur bus stand(Red swaraj mazdas of KSRTC which stop everywhere-Even long distance TNSTC buses have a stop at E.City) or Hosur-Attibelle(Attipalli in Tamil) Town buses and 360 from there to Electronic city.