You will want the MECA system Number 1. The frequencies and talkgroups are found here:
http://www.radioreference.com/modules.php?name=TRSDB&sid=322
There is a MECA system Number 2, but that system has mostly non-emergency communications like transit buses, street department, sewer department, etc.
The last time I was in Indy (earlier this year), the MECA systems were NOT digital but plans are underway to convert it at some point. MECA-1 is a very busy system!
I have PRO-94 which I use in Indy and have had ZERO problems monitoring my favorite talkgroups.
A little bit of Indianapolis scanner history....
I lived in Indianapolis in 1970 when the IPD used only TWO VHF frequencies for the entire city (155.01 East Side and 158.85 West Side). The Marion County Sheriff was on 155.61 and Speedway PD was on 155.7. IFD was on 153.77 and later added 154.175. There were no repeaters, either. Cars talked to each other directly on their dispatch frequencies, but talked to the dispatcher on another frequency, which was not repeated to all units. If a unit wanted his message to be transmitted to everyone (like an ATL message), he would ask the dispatcher to keep the dispatch mike open and the message would be manually repeated from the dispather's console from the incoming mobile unit transmitting on the incoming frequency and relayed out on the dispatchers frequency...(a maually repeated message, if you will). The audio quality was not great when they did this... Differenct departments could talk to each other on 155.37 or 155.475. In about 1973 or 1974, IPD dropped the VHF system and began using 8 UHF frequencies in the 460 MHz range which WERE repeated. Scanner enthusiasts at the time thought the "world had ended" because UHF scanners were few and far between (and expensive!). When that system came on line, I bought the Regency Whamo-10 scanner which could be programmed without buying crystals for each frequency. I still have that antique today!!! And it still works.... Crystals were about $5 each and a hobbiest could easily have a fortune tied up in crystals!
