in basic soil modeler when we input all values for every run we have to input all these values again & again.
how to save these input values in basic soil modeler ?

when you convert the model, CII automatically makes another file with the same name of the original file's name appending by a "b". in case you want to modify underground routing or do any other changes to the model, you should go back to the original file apply the changes and then go to the underground module, there you can see all your soil input preserved.

But if soil application on pipe will change during modification. (means Point where pipe is coming in and out/ Tee is mentioned) you have to convert that file again in buried file (appended by b)

Yes you have to convert the model again (basically re-mesh the system). However, the soil properties saved in the original model typically don't change.