Its 800 hours to be a standalone IRI, and 200 hours if you are already a FI
FCL.905.FI FI — Privileges and conditions
(g) an IR in the appropriate aircraft category, provided that the FI has:
(1) at least 200 hours of flight time under IFR, of which up to 50 hours may be instrument ground time in an FFS, an FTD 2/3 or FNPT II;
(2) completed as a student pilot the IRI training course and has passed an assessment of competence for the IRI certificate; and
(3) in addition:
(i) for multi-engine aeroplanes, met the requirements for the issue of a CRI certificate;