Index replication requirements for Debt ETFs ensure issuer diversification, duration alignment and investment grade credit quality. Prescribes norms for Debt ETFs/Index Funds including issuer level aggregation, minimum issuer diversification, single issuer weight caps, investment grade constituent ratings, and defined maturity criteria. Funds must replicate indices fully where feasible; permissible substitution rules allow same issuer issuances within a duration tolerance and, if necessary, substitution from other index issuers or non index issuers up to a portfolio cap, while maintaining portfolio duration close to the index. Deviations must be recorded; downgrades below required rating trigger prompt rebalancing. Issuers must publish index methodology and constituents and ensure quarterly compliance and transitional adherence.