You just need to be careful when doing these things. Get the stamp paper from licensed vendors. And the market value will be published for the locality in Mysore your property is in. Accordingly you will have to pay the stamp duty.
You will need a stamp paper of Rs 10 along with the application. There is copying fee for the photocopy. Rs 3 per copy and Rs 5 for every 100 words needs to be paid. It is highly recommended not to go via agents if you are dealing with your own property.
Well there is indeed a certain procedure involved. Any random person cannot go and obtain. Since in your case you are dealing with your ancestral property, you will be entitle. But you have to produce authorization of being a representative of the claimant. Generally copies of registered deeds are available to agents/ executants and claimants.
See, as far as I know, it is open to all. Anyone can obtain the certified copy for the documents. You will need to produce the will or death certificate of the original owner who is called the testator. And this applies to any immovable property, be it residential or commercial.