Procedure for extending immigrant visa

[neemask]

Hello
My parents got an immigrant visa with a 6-month validity. The visa expires in 2 months, however, he is not able to wrap up his business in time. Is there a procedure to extend the visa, and what are considered valid grounds for extending the visa expiration date. Any help or guidance appreciated.

Thanks

[AC360]

Hi . I have a similar situation. Can you help if you were able to figure this out ? What did you do ? Did you ask for visa extension ? Thanks.