Rome offers plenty of solutions meeting different requirements in terms of budget and comfort.
The local conference organizers suggest to find the most suitable solution on the several platforms active on the Internet or asking to a trusted travel agency. In terms of logistic the best choice is to identify the accommodation along the line A of the Underground between Termini (which is also the main railway station in Rome) and Anagnina (which is the last stop of the Metro A line). In this way you can reach the conference location in 20-40 minutes, going out of the city, and city centre in 40-20 minutes (going towards downtown) in case you want to enjoy a walk after conference end of day.
In alternative, you can choose the accommodation along the line C of the Underground between San Giovanni and Torre Angela but to stay at (more or less) the same distance from the conference location and from city centre don’t go beyond Pigneto stop or Mirti stop.