Latest Answer: @Saras,
And the disadvantages of not registering a sale agreement was specifically highlighted by the apex court in its judgement in the TG Ashok Kumar Vs Govindammal case in 2010.
Where an unethical property developers enter into agreements of sale and take huge advance money, and then sell the property to others, thus, pushing the original agreement holder and the future purchaser into litigation. Registration of agreements of sale will reduce such litigation.