Multiple Conditions on an IF statement

Hi,

This may be very easy or at the same time not possible, but i appreciate the help.

I have the following

G2 - Calculates the days before or after a date in M2, if cell T2 is blank, if populated with a date, it clears the cell.

Formula: =IF(T2="",NETWORKDAYS(NOW(),M2),"")

What i want to achieve on top of this, when M2 is empty G2 defaults to -49827 days, i would like for this to default to "TBC"

I have attempted this but cannot get it to work. to note cell U2 uses the following to calculate target date difference in days.

Any clues?

Superb. Thanks