Will 54bit driver kit is enough for tear down mac mini 2014?

Yes.

Here's the teardown: https://www.ifixit.com/Teardown/Mac+Mini...

Here's the tools needed to do it: Tools

Plastic Opening Tools

TR6 Torx Security Screwdriver

T5 Torx Screwdriver

T9 Torx Screwdriver

Here's what in the kit:

Bits Included:

Pentalobe sizes 2, 5, 6 (iPhone, MacBook Air, MacBook Pro)

Flathead sizes 1, 1.5, 2, 2.5, 3, 3.5, 4 mm

Phillips sizes #000, #00, #0, #1, #2

JIS sizes 000, 00, 0, 1

Torx sizes T3, T4, T5

Torx Security TR6, TR7, TR8, TR9, TR10, TR15, TR20 (compatible with non-security)

Hex sizes 0.7, 0.9, 1.3, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6 mm

Square sizes #0, #1, #2

Triangle size 3 mm

Tri-wing sizes #0, #1

Nut Driver sizes 2.5, 3, 3.5, 4, 5 mm

https://www.ifixit.com/Store/Tools/54-Bi...