Answer

In Dharmachakra Tap, a total of 108 upvas are traditionally observed.

Explanation

Dharmachakra Tap is a Jain austerity connected with deep devotion, discipline, and purification of karma. The number 108 is considered spiritually significant in Jain tradition.

Takeaway

So, the required number of upvas in Dharmachakra Tap is 108.