Hey gubendran_vins!
I'm sorry to hear that you're having trouble getting your object to spawn in the right place, I understand how that could be irritating. Regarding the issue you mentioned, my first suggestion would be to use the MRUK surface utilities to find the closest point on the detected floor surface. If the anchor's origin is misplaced and you've set the object's transform to the anchor's transform, it's possible that the anchor's pose is offset from the real floor and the object won't spawn in the place you want.
If you're still having trouble getting the object to spawn in the right place, you could also try using the Environment Raycasting API to more precisely place your object. We have some great documentation that covers each of these topics, and I can link the pages below.
Hope this helps, and please feel free to let me know if you have any questions or need any more help!
Spatial Anchors
Mixed Reality Utility Kit – Manage and query scene data
Mixed Reality Utility Kit – Place content with scene data
Mixed Reality Utility Kit – Instant placement with Environment Raycasting API
-G
