Hi
1) In the state of Tamil nadu, Hindu succession act was amended in the year 1989.
2) The amendment brought out with effect from 25-3-1989 has removed the distinction as regards to a son or a daughter. So technically with effect from 25-3-1989, all living and new born daughter's were eligible to succeed to ancestral property
3) So in your case, the Alleged will made in the year 2005 has no material value at all as your father cannot make any Will of any ancestral property and more so when your right to succeed to ancestral property was established vide tamil nadu hindu succession act amendment.
4) Oral partition is valid for movable properties. However when there is claim for partition of immovable properties, the same should be registered . If there is no registration of partition deed when partition involves immovable properties, then the Oral partition is not Valid. In your case since registration of partition instrument did not happen in the year 2005 and not sure whether there has been any registration of any partition deed and hence oral partition is invalid.
5) Moreover since you had filed the case in the year 2011, the WILL made by your father in the year 2013 is open for challenge under the grounds of Coercion and Undue influence and hence will not be a valid Will.
6) You can get the details of properties mortgaged to the bank as collateral from your sub-registrar office. Since banks provide loans only after registration of mortgage, you can obtain the details of mortgages made by your brother's from the nearest sub-registrar office where properties are located.
7) In your case, since all of the properties are ancestral properties, you will win your case on the following grounds
a) Oral Partition - NOT VALID since it involves immovable properties.
b) WILL - Can be made only for self acquired properties and not ancestral properties. More so Any WILL made under coercion and undue influence is Totally INVALID.
c) Your right to succeed to properties is vide Tamil Nadu Hindu Succession amendment act 1989 (not 2005).
d) Partition Deed involving immovable properties should be COMPULSORILY Registered.
Hope this helps.
All the best.