Hi Parvez,
Got the solution to make the enable field of "Base Unit f Measure" in MM01 Basic Data 1 Tab.
TO resolve this issue you have to do these following steps -
SPRO>IMG>Logistic-General>Material Master> Field Selection>Assign Fields to Field Selection Groups -
Click on the Field Selection Maintenance Button
Click on the details Button.
Check all the selection group and make sure you didn't check Field selection as Hide for any selection group.
After making these changes the Base Unit of Measurement will be enable in MM01 for "Basic Data 1" Tab.
Reward will be appreciated.
Thanks & regards,
Ankur Chauhan