Short answer. Generally, no. A partition made by the testator cannot be challenged merely for lesion — receiving less than a sibling is not by itself a ground to rescind it — unless your legitime as a compulsory heir was actually prejudiced, or it appears the testator's real intent was different from what the partition shows.
What the law says
The partition made by the testator cannot be impugned on the ground of lesion, except when the legitime of the compulsory heirs is thereby prejudiced, or when it appears or may reasonably be presumed, that the intention of the testator was otherwise.
Civil Code, Article 1099 — Partition by the Testator. Read the full provision →
Lesion alone is not enough against a testator's partition
The statute closes off the ordinary route: a partition made by the testator — as opposed to one the heirs work out among themselves — cannot be impugned on the ground of lesion. Simply pointing out that you received less than your siblings, without more, does not give you a basis to have the partition rescinded. The law gives a testator's own division of the estate a measure of protection that an heir-made partition does not automatically enjoy.
The first exception: your legitime was actually prejudiced
The rule yields where the legitime of the compulsory heirs is thereby prejudiced. If the smaller share you received actually cuts into the legitime the law reserves for you — not merely receiving less in the free portion, but receiving less than your protected legitime — that is a recognized ground to challenge the partition, and the general rule against attacking it for lesion does not shield the testator's division in that situation.
The second exception: the testator's real intent was different
The statute also allows a challenge where it appears or may reasonably be presumed that the testator's actual intention was otherwise than what the partition on its face shows. This addresses a situation where the written partition does not genuinely reflect what the testator meant to do — perhaps due to an error or a discrepancy between the stated division and the testator's evident wishes elsewhere in the will.
What you would need to establish
To succeed on either exception, you would need to show more than a bare inequality between your share and your siblings' shares — either that the inequality actually invades your legitime specifically, or that there is a genuine basis to believe your father's true intent differed from the partition as written. Absent one of those two showings, this article leaves the testator's partition standing even where it results in unequal shares among the heirs, since an unequal division by itself is not the wrong this provision is designed to correct.