how can filed a divorce case.

Facts posted by you are ambigous and vague. Post in simple language if you are seeking obligation of experts on this platform.

However, it is advisable to consult a local lawyer for appreciation of facts, professibnal guidance and necessary proceeding.

Your post suggests the facts as follows:

my elder brother,a dibayng person

without any dowry.my father given her all aurnaments & ceremony expenditure

we are lower middle class family,we have a grocery shop. my mother ,house wife she is austioartharites patient & right leg fractured) .my father diabetic & heart patient ( he is no more,26th December 2018 he is expire of heart attack).

The wife according to you wants

"they all pressurized & mentally torturing my brother.they told him to separate from us"

Now your post caption is  "How we can filed divorce case" ?

Divyang person is dependent on some other healthy person, father deceased, the mother is also having old age problems and incapable..Who is there to look after such a person if not the wife?

Whose idea is such divorce ?  (Neither wife nor her husband your brother)

It appears that though he is Divyang, he is earning some thing to support the family .  Is there any one who can look after divyang person better than his wife ?   

Let elders sit and settle the case though it has failed twice in the past.  Have mercy and stop torturing that poor soul of your brother further.  Let him take his own decision on his life.
 

Yes, the facts posted are confused. Please post simple facts bringing out the real issue, if any.