How to safe house

1. No such law when half dozen cases your sister already filed on your BIL and when such cases are already pending. However file Complaint case under DV The Act 2005 too and get "protection order" such as rights to residence in that property and for not alienating her and their kids from said property till disposal of final matter under DV The Act. It will take years to dipose such complaint case and till that time she can keep locked her portion of the property and live at her natal home. That way he cannot sell the property but if he wants he can still run-away to another State.
2. Approach Hon'ble SC for transfer of case from Faridabad to Haridwar first. Then file DV Complaint case form Haridwar.

Instead get an idea of valuation of his house in Faridabad. Ask that much amount as alimony or for compromise of all cases and secure your sister and her kids future by arranging for her re-marriage and as financial security for kids.  The half dozen cases does cost some money in terms of lawyers fees and years spent on litigation think on them too in best interest of your sister and her two kids.

No useful purpose will be served on one side you are thinking to bring her to natal home and your heart is in BIL property which is in another State whose owner has already got himself re-married. Even post his possible conviction your sister will only be left with "residence rights" on his Faridabad property minus a husband so what good gift that shall bring to her other than escalating property valuation which she cannot sell in her lifetime without owners signature nor Law can force then her ex-husband to sign on property papers till his lifetime! Also take note his second wife also has some rights and god grace if child pops from his second marriage then s/he also have legal rights on this property too. It is complex and not that easy as rosy picture some legal mind might have told you is my view whether you like it or not.  

We are sure you will think again on above lines and make a long term consious decision in better interest of your sister and her two minor childrens instead of come running here for quick - fix remedy.