IPC Section 121 is now BNS Section 147

IPC 121 (Waging war against the Government of India) → BNS 147 Waging, or attempting to wage war, or abetting waging of war, against Government of India

Verbatim · BNS 147147. Waging, or attempting to wage war, or abetting waging of war, against Government of India.— Whoever wages war against the Government of India, or attempts to wage such war, or abets the waging of such war, shall be punished with death, or imprisonment for life and shall also be liable to fine.

Read the full BNS Section 147 →

Offences committed before 1 July 2024 are still charged and tried under the IPC; the BNS applies to offences on or after that date.

Old-to-new correspondence is indicative and not always one-to-one; read the new text itself.