Explanation:

- Option 1: Doomara, Ajmer

- This is not the location of the National Research Centre on Seed Spices.

- Doomara is known for other agricultural activities, but not for housing this research centre.

- Option 2: Mandore, Jodhpur

- Mandore is famous for its historical and archaeological sites.

- It does not have the National Research Centre on Seed Spices.

- Option 3: Beechwal, Bikaner

- Beechwal is recognized for its agricultural research stations.

- However, it does not host the National Research Centre on Seed Spices.

- Option 4: Durgapura, Jaipur

- Durgapura is another prominent agricultural research area.

- But this is not the correct location for the National Research Centre on Seed Spices.

- The correct location is Ajmer, specifically at Tabiji, not Doomara. The official and proper name is "National Research Centre on Seed Spices, Tabiji, Ajmer, Rajasthan."