Indexation based on UDS registration or flat handover year

This discussion clarifies the correct financial year to use as the base year for calculating capital gains indexation on a flat in Chennai. The user registered their Unregistered Development Rights (UDS) in FY 2009-10 and took possession after construction completion in FY 2011-12. The consensus is that the UDS registration year (FY 2009-10) is the legally correct year of acquisition for indexation purposes, not the handover year.