The Bombay High Court is one of the oldest and chartered High Courts in the Country. The Charter of High Court of Bombay was issued on June 26, 1862. This seems to hold good for Kolkata and Chennai. All of them were Presidencies during British Rule.
Presently, in Maharashtra, applications for Probate, Letters of Administration and Succession Certificate have to be filed in Mumbai High Court. In other States, it can be done in the court of District Judge.
There is no valid reason for this system to continue in independent India. Actually, there may be hundreds of such laws and practices which have no place now. The only problem is that Government does not care to listen to us.