Sale to agreement holder can became a party in suit of declaration

Okay, what is that you want to clarify from this forum.

You said that you purchased the property from Mehta whereas the vendor has filed a suit for declaration of title hence the title to the vendor is defective, if you want to participate in the proceedings, you can very well do so if you are affected.

Pls provide me any judgment regarding this 

The query suggests itself to be a moot court question than a legal query.

We don't supply judgements here in this forum.

You may ask your own advocate for this.

Purchasing property through sale agreement  does not confer your title ownership of property so it can not be said that your rights are affected  your presence is not required/necessary for just decision of case so your applicatinu/ order 1 rule 10 cpc is not maintainable. .

Yes  he can become party to declaration suit if he is affected. 

I think there was a very recent judgment of Supreme Court of India which said a sale agreement does not give any interest in the property to the buyer. 

In view of the above judgment of the Supreme Court of India, It appears that your application under Order 1 Rule 10 of CPC is not maintainable. 

Just becaise you signed a sale agreement, it would not confer any right on the proeprty. 

However, you can personally meet experts, show them all the papers and find out. 

Is the sale completed or not?

Or, is it still at the stage of agreement?

Why was a declaration suit filed? What exactly is the declaration sought? 

Facts posted are vague and incomplete, if it is a true story, which is prima facie  a moot court topic for debate.