Essential Elements of Sale:

A minor or lunatic cannot be a transferor / vendor as he is not competent to contract under Section II of the Indian Contract Act, 1872. However it has been held that a minor or a lunatic can be a transferee or purchaser in the case of transfer by way of sale or mortgage, represented by his Guardian.

Subject matter is the transferable immovable property.
 

Price is an essential ingredient for all transactions of sale and in the absence of the price or the consideration, the transfer is not regarded as a sale. The transfer by way of sale must be in exchange for a price. It has been held that price normally means money. The price can be paid fully in cash or it can be partly paid and partly promised to be paid in future. The price can be fixed by the agreement between the parties before the conveyance of the property. The price is to be fixed reasonably.

Delivery of Property:

Transfer by way of sale in the case of tangible property worth less than rupees One Hundred can be made either by a registered instrument or by delivery of property by putting the purchaser or the person directed by the purchaser, in possession of property. If the consideration for the sale is more than Rs.100/- then the instrument must be registered under the Registration Act, 1908.