Illegal Encroachment and Damaging the property in name of repair

My Father had bought a flat in Mumbai years ago where along with my parents i lived with my 2 younger brothers. After parent's demise we brothers moved to different places and also we had an internal settlement where it was decided that i would own half of the property and the other half be divided between my other two brothers. The house was given on rent to different party and the share of rent was to be divided as per the property division among 3 of the brothers. My youngest brother has now encroached inside the property and the tenants who used to stay in the house have now vacated due to excessive hooliganism displayed by my youngest brother. he has somehow managed to steal the share certificate where in it is mentioned he owns 25% of property and has managed to sit inside the house and we couldn't do anything. Now, he has started altering the house( i call it damaging) in the name of repair without any of the permission. What legal actions can be taken against him? I own half of the share to the property and my other brother is in my favour.With 3/4 th property under our control what actions can be taken? i stay very far from mumbai . so it makes it very difficult to get into scuffle like this.