Step 1: Recall the conference details.
The National Conference of Women Thinkers titled "Bharti-Nari Se Narayani" was organized in 2026 to integrate women's leadership with the Viksit Bharat 2047 vision.
Step 2: Identify the host state.
Uttarakhand hosted this conference, which brought together women thought leaders from across the country to discuss their role in building a developed India.
Step 3: Eliminate the distractors.
Maharashtra, Tamil Nadu, and New Delhi did not host this conference. New Delhi is also a Union Territory, not a state. Uttarakhand is the correct answer.
\[ \boxed{\text{Uttarakhand}} \]