Since nature of the list is prohibition , Mr. B wants legal opinion about the sale deed has clear title ?
B should obtain legal opinion about this by producing the relevant documents and details before an experienced local advocate.
The advocate shall scrutinise the papers and all other relevant rules in this regard shall render his opinion with his recommendation to buy or not.
Is prohibition survey no(s) any are relation to plot no: 123/part in layout?
Without ascertaining the fact that whether this plot no. 123 falls within the list of properties under prhibition from the land revenue/record department, it cannot be confirmed, so you may ask the vendor to provide details in this regard.
How legally M/S Developers Ltd, developed the layout and made plots and sold to Mr. A ?
How do you say that the developers have done this layout legally.
The approval might have been obtained after bribing the corrupt officals too, who knows what has happened in the background without verifying the details.
Any legal issue in later if Mr. B purchases house on plot no: 123/part in layout from Mr. A?
The hidden dangers cannot be foreseen especially when the builder as well as the vendor combinedly assure to get the problems rectified when it emerges at a later stage in this regard.
But to your shock and disappointment nobody will come to your rescue at the time of crisis, especially when the authority issues legal notice for demolition of the construction constructed on the prohibited land.
Some honest officer of the department will dig out the sordid affairs and the scams or scandals of the past.
That time all such problems will arise,
Then neither the builder nor the vendor will come for your help or stand by you to support your claim.
Take wise decision after ascertaining the facts and obtaining a proper legal opinion about this before buying the property.
Who will provide more information in this concern
It is the duty of the vendor to provide information or you can dig out the information through your own sources, or approach the land revenue/records department of the state government to ascertain the factual situation .