According to the search results, the states at the bottom of the Composite SDG India Index 2020-2021 as per NITI Aayog are Bihar, Jharkhand, and Assam. This information is confirmed by multiple sources, including Times Now News and IAS4Sure, which both list these states as the worst-performing in the index. Therefore, the correct option is 1: Assam, Jharkhand, Bihar.