You can obtain the last transaction on the property by visiting the office of Sub-Registrar giving particulars of  property. Only than you can certain of the situation. There are people Kolkata who provide such type of service.

Take 30 years title search in sub registrar office to check whether there has any recent transactions in respect of said plot 

If it's sold and possession given then it can't be said to be in your hand

If the revenue records periodically being updated by the revenue department shows your father's name under the landowner's name, then it shows that the land has not been officially mutated in any third party's name but only in your father's name and as per revenue records, your father is the owner of that land.

Take the help of Revenue Inspector/Surveyor of the jurisdictional Corporation/Municipal/Municipality office and find out the property's location and fence it.

Dear Client, 

                     You may contact the local District Land Reform Office (DLRO) office for obtaining further more information related to this particular land as they usually record various transactions that take place in relation to a particular land in their district.

Thanks & Regards   

If the property is on your father's name then you should have some document to prove that this landed property belongs to you.

The information provided by the website of the government may not be reliable because it is revenue records.

You may better get the encumbrance details from the website of the registration department.

If there is any encumbrance showing that this property has been alienated or any other name is found in the title transaction of the property, you may obtain the certified copy of the registration document and verify if the transaction is genuine and the sale  of property was executed by your father or who?

You cannot ascertain the details in the absence of the documentary evidences to confirm the title of the property  and for that you may have to rely upon the registration documents alone and not the revenue records. 

- Since, your fathers name is showing as the owner of the land , then you can confirmed from the office of the registrar , and for knowing that whether had sold the land or this is in his ownership till date. 

- Yes, mutation is not mandatory to be the owner of a land , and it is for paying the property tax . 

1. Mutation does not confirm/signify ownership of a land, registered Title deed does.

2. So, conduct registry search in connection with the said property to know the flow of ownership of the property after your father, since deceased, had acquired it's ownership through a valid deed of Conveyance.

3. If there is no record of further sale of the said property then it shows that it has not yet been sold.

4. However, it is possible that your father had availed loan from a Bank duly mortgaging the said property for which the original title deed is to be deposited with the lending Bank.

5. If the loan amount is not paid, the Bank can initiate SARFASI proceeding and sale the land to recover the dues.

6. In the above case the Bank shall have to register the said mortgage with Central Registry as otherwise it can not initiate SARFAESI proceeding.

7. So, to find out whether your father, since deceased, had mortgaged the said land with anty Bank or not, you shall have to conduct search with the said Central Registry.

You should visit sub registrar office of the area where the properties located and apply for encumbrance certificate of the property which will contain the change of ownership of the property. 

Mutation records does not confer any title at all.

With help of local advocate you get a search report of the concerned property.