Hi
First all of the legal heirs of your brother (including you ) should sign a settlement(also called release/relinquishment deed) deed where in all of the other legal heirs agree to relinquish their rights on the properties so owned by your brother and thereby transfer the property to you. The settlement deed has to be registered at Sub Registrar office by payment of Stamp Duty and Registration charges.
With reference to Jointly owned property,a separate settlement deed (also called release/relinquishment deed)has to be entered in to by the legal heirs of your brother and registered at sub-registrar office after payment of stamp duty and registration fees. However especially with reference to this property, you will need to discuss more as we need to see the sale deed/partition deed by which you and your brother became the owners of property. the reason is depending on the language of the deed, sometimes the property might have been transferred based on Either or Survivor. if this(either or survivor is explicitly mentioned) then you just need to mutuate the property in your name. Or else you need to enter in to a separate settlement deed
With reference to cash/cheque transaction- you need to mention both the cash component and cheque component along with the date of cheque etc. Better to show the cash and cheque component (all white) for the reason that you have a authentic source of income(Sale of property).
Sale agreement does not have any expiry date. if the cheque issued by the buyer bounces, then the sale agreement does not become VOID. You have to file a civil suit for cancellation of sale deed and recovery of possession, a civil suit for recovery of money and also a case under 138 NI act for cheque bounce.
So ideally settle for DD only
Hope this helps.