Thank you so much for explaining. After Lesson 6 I understood more clear way 0 or 9 there will be no contradiction to the solution.
In the Practice HW book color the Vedic grid I am just curious to know if there are any other observations.
My observation is all the digits except 3,6 and 9 … the digit repeats 6 times. For 3 and 6 – digit repeats 12 times and 9 repeated 18 times.