Why this matters
Many US-based NRIs assume a will needs a notary because US state wills often include a self-proving affidavit signed before one. That is a US convenience for proving the will later in a US probate court. Indian law does not have an equivalent requirement.
What Indian law looks at is the signing itself: your signature, and two witnesses who each saw you sign (or heard you acknowledge your signature) and then signed in your presence. Get that right and the will is formally valid, wherever in the US it was signed.
What NRIs should consider
A notary can still help as evidence
A notarized signing records who was present, when and where. That can make it easier to answer questions if the will is later examined in India. It is optional.
Apostille is generally unnecessary
An apostille authenticates a public document for use abroad. A will is a private document and does not need one to be valid; some families add it for extra formality.
Consulate attestation is optional
Attestation at an Indian consulate is not required for validity. It mostly matters for other documents, such as a power of attorney used in India.
Witnesses matter far more
Use two adult witnesses who inherit nothing under the will, record their full names and addresses, and sign in one sitting.
Registration is a separate question
Registering a will at an Indian sub-registrar's office is optional under the Registration Act, 1908 and does not depend on notarization.
Example
Priya, a US citizen in Texas, signs her India-only will at home.
Two neighbours who inherit nothing watch her sign and then sign themselves. She does not visit a notary. The will is formally valid for her flat in Pune; she chooses to keep the original in a fire-safe box and emails a scan to her brother, the executor.
This example describes general considerations only. It is not advice about any particular person’s situation.
When professional legal advice may be appropriate
Consider speaking with a lawyer qualified in India if your estate spans several countries in a complicated way, if significant tax planning is involved, if a family dispute or contested estate is likely, if a business, trust or unusual ownership structure is part of the estate, or if you are unsure how a Will made where you live interacts with one covering Indian assets.