Can I ask for settlement

The presumption is that you might have purchased a property which is in dispute among co-sharers, and as you are the purchaser, they have also made you a party.  Unless you are summoned there is no need for you to take part in the proceeding.

Without facts and your relationship with the sellers and your knowledge on disputes etc., proper guidance is not possible.  You are evincing interest means that you are aware of the dispute and might have withheld some amounts with you without paying to the seller, and obtained such letter of authorization from the seller to keep that part of the consideration as security and in case of disputes can utilize that amount towards payment to the other co-sharers.  If you are innocent third party buyer you need not worry, and it is in your interest that you have to get acquaint yourself with facts to rule out collusion in between the parties in the suit.