1) if there is no other access to plot B and C they can claim easementary right of necessity

2) plot holder B and C cannot object to purchaser of back side of plot A using the common passage

Section 13 of the Indian Easements Act deals with easement of necessity An easement of necessity means an easement without which the property cannot be used at all. Mere convenience is not the test of an easement of necessity. It can be claimed only when there is absolute necessity for it, i.e. when the property cannot be used at all without the easement and not merely where it is necessary for its reasonable, or more convenient enjoyment. A man cannot acquire a right of way as an easement of necessity, if he has any other means of access to his land however more inconvenient it may be than be passing over his neighbours.

2) they can use common passage if there is no other access to their plot

The owner of plot B and C can deny access to plot A unless the use of passage is necessitated by absence of an alternate path to reach the plot. If there is easement by necessity then restraint on use of passage can be remedied by the aggrieved owner by filing a suit for injunction in the court.

Their is a common passage with a blind end to plot A. While reaching plot A from main road common passage is also passing adjacent to plot B and C. The plot back side of A do not have approach road . If some body buys plot A, and also the plots on the back side of A, and use this common passage for plot A as well for plot back side of A , can plot holder of b and C raise objection as per law.

The vacant site behind plot A is not a new emergence. This should have been divided from an existing property. So from that partition or division, there has to be a mention for the approach pathway from road to the vacant sit and vis a vis. Have you verified the property document about this? There has to be some arrangement to this. This will not be a new problem.

The approach for the vacant site at the back side of plot A should be available on the other side. It is not necessary for the B and C to allow A to use this common path for the people occupying the back side vacant site of plot A. They can very well object and obstruct the usage, the solution will be available in the court alone by convincing the court about the easement by necessity.

Please clarify easementary right of necessity , will this prevent the resident of plot on the back side of plot A to use the common passage even though it becomes common with plot A ,if somebody buys plot A and also plot at the back side of A , which have access through narrow lane

The easement of necessity for the plot at the backside of the plot A will not be applicable.

However based on the sole ownership, the owner of plot A can file a suit for easementary rights and can claim easement by prescription.