Reg. Entry after approval of Visitor Visa

[mojo123]

Hi,
my in-laws already approved for 10 years of visitor visa.
is it necessary to get entry in US within first 6 months?
i heard that they have to enter in US with in first 6 months after visa approval o'wise later on they could have problems for the same.
is their any such kind of rule or this is just a rumor.
thanks in advace.
Mojo

 

[dahlia]

One can enter any time before the visa expiry date.