Unfortunately, you are asking questions on facts of the case, and more so, when the facts appear to be complicated and twisted. One set of facts on record and another verbal. Please do not expect any good advice on facts of the case from a person who has not even seen the documents.
But, in general, let me point out that it is not uncommon in India to have cash component in property transactions. One value is shown in the sale deed while an extra amount is paid in cash. Further, though you have not made it clear, it appears that the property was sold by your mother and probably also by your brother, so they are perhaps mentioned as sellers in the sale deed, while you have given your consent for the sale (may be perhaps because you might also have been a successor to the property). Now, here again, it may not be uncommon for the person giving his consent for sale of a property (in which he may have some right, defined or undefined) by others, accepting some consideration for giving his consent. A person may give his consent to a sale either due to natural love and affection towards the seller (in this case, your mother / brother), or one may receive a consideration for giving such consent. These are things which depend on the facts of each case. But, technically, it is possible that an allegation can be levelled that the person giving consent had received a consideration. So, such an allegation may not always be a wild or baseless allegation, and may need to be defended properly instead of being confined to dust-bin at the outset by saying it lightly that how can a person giving consent could have received an amount.
More than what is mentioned above, it is not possible to comment in the absence of knowing facts of the case.
My advice to you would be to engage a good lawyer, show him all documents and discuss with him all relevant facts, and obtain his advice. If you are not satisfied with your existing lawyer (as it appears from your different questions), then you should consider changing him. But, please note that you cannot get good advice from someone who has not seen detailed facts.
Dr. Ashok Dhamija is a New Delhi based Supreme Court Advocate and author of law books. Read more about him by clicking here. List of his Forum Replies. List of his other articles. List of his Quora Answers. List of his YouTube Videos.