Legal value of agreement on non judicial stamp papers

The agreement has evidentiary value and will be treated as such. Whether a party succeeds or not will depend upon what all evidences he brings to support his case. Maybe you also need to look into whether such roads are allowed in the plots per local land usage laws to begin with.

Thanx Hardeep for the prompt reply, However can you clarify whether such agreement  without registration in a sub registrar office is binding on all parties as it seems to be an agreement of immovable property creating certain right to free  path for all signing members as well as third parties. What if one party after signing this, doesn't want to let off his certain part of plot for path? Further, why only 1000 rs stamp paper...can it be more or less?

As already said, all agreements - even oral - have evidentiary value, depending upon how can they be substantiated / corroborated.

Re property yes indeed most agreements creating rights etc on it would need to be registered. That does not mean, however, that a prima facie case can not be built on an unregistered agreement. The Court , other evidences, lawyer skills etc will be the other factors . That is the fact of our legal system, else there will not be baseless cases clogging it up for decades.