Ion and Neutral Mass Spectrometer (INMS) data sets are archived by the PDS Planetary Plasma Interactions 
PPI Node at the University of California, Los Angeles.
User's Guide - on line at the PPI node
Titan 
Ions User's guide
Titan 
neutrals User's guide
Locating and Importing Data from the PDS
Raw Data Products
Level 1A Data (REDRs) - 
Online Access     
Telemetry Packet Data - 
Online Access
Higher Order Products - 
Under Development -  Titan neutral and ion density profiles.
Other Useful Products for Interpreting the Data
See table of 
INMS observations (
xls, 
txt)
See the 
Master Schedule for a time ordered listing of observations by all instruments.
SPICE - Archived Cassini SPICE ancillary data providing observation geometry (positions, orientations, instrument pointing, time conversions and the like) are available from the PDS 
NAIF Node.
Publications - A listing of team members to facilitate literature searches.