Regarding family visa

hii sir
i want to know about family visa in bahrain for my sister. my brother in law is living there . can u give me details regarding it. how  she can get it . what fee have to summit and for how long she can get visa

See this for the requirements:

http://lmra.bh/portal/en/page/show/189

The validity is linked to the sponsor's work permit.  Whatever the duration of that i.e. 6 months, 1 year or 2 years; she will get the same.

And your brother in law's sponsor/company has to apply for her visa.

thanks a lot sir