Explanation:

Let's look at the options and find out which one is correct:

- Option 1: 1st April, 2002

- This is not the correct date when the Code of Civil Procedure (Amendment) Act, 2002 came into force.

- Option 2: 1st June, 2002

- This is not the correct date either for the commencement of the amendment act.

- Option 3: 6th June, 2002

- This option is incorrect as well for the enforcement date of the amendment.

- Option 4: 1st July, 2002

- This is the correct date when the Code of Civil Procedure (Amendment) Act, 2002 was brought into force.