Custodian regulation requires online registration, detailed daily transaction reporting, vault security standards, and AI/ML disclosures. SEBI's Master Circular consolidates custodian obligations: online registration via SEBI Intermediary Portal; mandatory integration with clearing/settlement systems; quarterly vault specification submissions referencing RBI technical standards; and extensive scheduled reporting - daily DTR/DTS (XML) with ISIN-based identification and unique trade IDs, fortnightly ISIN-wise AUC, fortnightly debt reports, monthly AUCs, maturity-wise debt breakups, quarterly operational reports, audited annual accounts/networth certificates, and annual expert system reviews - together with prescribed file formats, coding conventions, amendment/deletion procedures, and penalties for non-compliance.