Sale of property without the consent of all the joint owners

Sir, The said property is in my mother's name and two aunts. My mother lives out of country and I live out of country. My both aunts very much wants to sell property. However due to past history of property acquisition it was decided that my mother will get more %share in property. Now, both aunts equal division. I really don't want property be sold if we don't get extra % share. Property is in my aunt's procession. My question is can they sell the property without our consent, and if they forge my mother's signature (they have long history of forging signatures) and sell property , what legal option do we have. Also, we might not know (for a while -may be year or so) that they sold the property behind our back, so how long do we have time to file fir after we come to know.