Here, you have to only consider the number of entries in the TLB and page size. All the other data like hit ratio and all is not needed.
TLB reach is the number of distict values that can be accessed by the TLB.
So,
TLB reach= Number of entries * Page size.
Here, page size is not given, but page size=frame size=4KB
So, page size=4KB
TLB reach= 64*4KB
=262144 entries
So, 262144 different entries can be accessed by the TLB.