False Dowry Case to my elder brother

We are two brothers.I am a married man & it has been around 1.3 years of my married life. My elder brother got married after me on 23rd July 2015. We have phone recordings that his wife was pressuring him to live at least 8 years nearby her residence in Rewari (Haryana). In starting my brother got a room on rent & settled in her colony, nearby her home for executing his married life. After a couple of months, his wife, sister-in-law, mother-in-law started to tease him to show them every type of expenditure, salary slips n all. where all the money he invests bla bla etc. They wanted to make him & work as a servant for them. He tried a lot to settle the things but it could not go long. On 29th Dec. 2015, our family members went their residence to sort out the matter but on 3rd January my father got a call from my brother's mother-in-law that they have called back her daughter at her home and there is no need to send my brother back. Now, they have all the luggage, gold, things at the house which is located in their colony and they have put a lock over it. My brother could not get anything from that house. Now, they have requested to "Mahila Thana" in Rewari to lodge a false FIR which claims that my brother asked her wife for 2 Lakhs rupees & tortured her. They have written mine & my wife's name too in that matter. FIR is not lodged till date but what will be the effect of this case on us as we are not guilty but as a family member we may be surrounded/caught in that case. What can be done to protect myself & my wife from such case. They have nothing against my wife as she did not talk to them anytime and in case of mine they have only whatsapp conversation which does not show I threatened or talked wrong to my brother's wife. In case, if they got FIR lodged against us, what action will be taken by the police & what can be done to protect myself & my wife in prior so that if we get into this matter, how we can get rid of this? As my wife is govt. servant, will it effect to her job? Waiting for your most valuable reply.