Marshalling refers in law to an arrangement. It is dealt within Section 81 of the Transfer of Property Act, India.
In this there will be one common debtor who has taken loan from more than one creditor.
Suppose A being the owner of two properties mortgages both of his properties viz 1 and 2 to X. Later A mortgages 2nd property alone to Y. Here if X proceeds to realise the debt due to him by A by way of loan from 2nd property, Y can compel X to proceed first against 1st property and then if the debt is not satisfied, to the 2nd property.
Thus Section 81 of the Transfer of Property Act protects the subsequent mortgagees from prior mortgagees with respect to property mortgaged to them.