Husband left home

My sister she got married on 25th of Jan was totally arranged marriage. After marriage they both were staying happily in bangalore.suddenly after a week she got a call from mother in law tht MIL and FIL are coming.she welcomed her nicely as a new daughter in law.1-2days it was ok but after tht MIL started her role of MIL don't do this don't go any where I don't. Like her gng office all idiotic stuffs which my sis followed for some day but all was difficult to follow in city like Bangalore tht keep pallu on it head always.don't go to office and my sis started raising voice and because of which she always had fight with her husband.always it incresed because of which MIL and FIL also got involved and started tourchuring my sis.After 2moths they left from bang to delhi for checkup.and I don't know what they said to their son he always keeps on fighting with my sis and one day sudden they had arrgument and he left home.nw none of the family memmber is talking to her.and we r not able to trace out any one .as they r not picking any sis is just 23 .we complained in bang police he called tht gye came he told to police tht he will go home and after tht again he is gone and not picking police ph also don't know what to do as we r not able to trance any one as she is new to the family