On the facts stated by you, the absence of prior court permission is legally significant, but it does not mean that you can challenge the sale at any time. Under Section 8(2)(a) of the Hindu Minority and Guardianship Act, 1956, a natural guardian cannot, without previous court permission, sell or otherwise transfer the minor's immovable property. Such a transaction is voidable at the instance of the minor, rather than automatically void. Indian Kanoon
The major difficulty in your case is limitation. Article 60 of the Limitation Act prescribes three years from the date on which the minor attains majority for a suit by the former minor to set aside a transfer made by the guardian. The Supreme Court has specifically held that a challenge to a guardian's alienation in violation of Section 8 is governed by this three-year period. Indian Kanoon
Therefore, if you attained majority in 1998, the ordinary three-year period would have expired around 2001. Merely because your mother did not obtain court permission does not, by itself, revive the limitation period decades later. A suit filed now seeking cancellation of the sale solely on the ground that you were a minor and there was no court permission would face a serious limitation objection.
There is, however, an important point that needs to be examined before completely abandoning the matter: whether the entire 2 acres standing in your father's name actually constituted your individual/minor share after his death, and whether the sale deed executed by your mother purported to transfer your specific 1-acre interest. The character of the ancestral property, the succession after your father's death, the exact sale deed, and the manner in which your mother's title/guardianship was recorded must all be examined.
Regarding your question about a thumb impression/signature taken from you while you were still a minor, that fact can be relevant but does not automatically overcome limitation. A minor ordinarily lacks contractual capacity, and the legal effect of any document allegedly executed by you while a minor would depend upon exactly what document it was, its contents, your age, whether it was registered, whether your mother executed it as guardian, and how the purchaser relied upon it. It would therefore be important to obtain the certified copy of the original sale deed and the complete registration record, including photographs/thumb impressions, identification details and endorsement of the Sub-Registrar.
There is also a distinction between saying “the sale was void” and “the sale was voidable.” Under Section 8(3), a sale by the natural guardian without the required permission is generally treated as voidable, meaning it ordinarily has to be avoided/set aside through the legally appropriate proceedings. The Supreme Court has reiterated this distinction. Madhya Pradesh High Court
Accordingly, I would not advise filing a suit immediately merely on the assumption that absence of court permission gives you an unlimited right to sue today. First obtain the 1992-era title documents, the sale deed executed by your mother, your father's death certificate, the revenue records, the family tree, and proof of your exact date of majority. Then the limitation issue, the precise nature of your alleged 1-acre share, and whether there is any independent ground to challenge the transaction can be properly assessed.
If the sale deed contains your own alleged thumb impression/signature, that document should be examined particularly carefully because it may raise additional factual and evidentiary questions, but it should not be assumed that it automatically defeats the limitation bar.
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