As per registration act, SDM has no power to decide right and title of party. And its role is limited to execute registrstion.

But can refuse to register transfer deed where property is mortgage and showing in EC.

Citation depends on full facts of the case you need to share and seek consultation to get correct citation

Kindly share your case in detail facts and issues.

As far as will is concerned  you have to file testamentary petition before district court or HC having jurisdiction 

if there is objections raised by legal heirs it gets converted into testamentary suit 

SDM cannot decide they issue 

- An SDM has no power to usurp the powers of the civil court , and to decide the title of property cases. 

-  Punjab and Haryana High Court has ruled that proceedings under Section 145 cannot be used as a tool to get possession of the land on the basis of title.

- Supreme Court of India Judgement on  Amresh Tiwari vs Lalta Prasad Dubey & Anr 

 Sub Divisional Magistrates exercise powers of Executive Magistrates. In this role they are responsible for operating preventive Sections of Code of Criminal Procedure.

You can peruse the below judgment:

This is a legal plea

These matters can be tried only by a competent civil court

However the SDM can touch upon these matters for collateral purposes but cannot give any decision on these matters which are disputed and which require appreciation of evidence by a civil court 

SDM has no power to usurp the powers of the civil court. 

The property rights have to be determined by the SDM. that is the law.

You dont need citation because it is specific law that SDM doesn't have jurisdiction to decide the the ownership rights of property.