Explanation:

- Section 511 of the Indian Penal Code deals with attempts to commit offenses not otherwise provided for. It applies to attempts to commit offenses except those punishable with a specific section other than 511.

- Attempt of theft: Section 511 applies. Theft is an offense, and attempts are covered under this section.

- Attempt of affray: Section 511 applies. Affray involves two or more people disturbing the peace.

- Attempt of riot: Section 511 applies. Rioting involves unlawful assembly and does not have a separate attempt provision.

- Attempt of murder: Section 511 does not apply. Attempted murder is specifically covered under Section 307 of the IPC.

Answer: Option 4: Attempt of murder