Easy way is the 4 thinnest from any guitar set for LINEAR tuning.
For re-entrant tuning, do the same, but replace the 4th (low-G) string with a single unwound steel string in a gauge a little thicker...
i.e., if your 'A' string is a 0.009" or 0.010", get a 0.011" or 0.012" respectively and put that as the 4th string
this is for GCEA
if you want DGBE tuning, then use the 'middle four' strings from a guitar pack and apply the same method as above for linear or re-entrant tuning....
otherwise you can search on the forum as this info with exact string gauges has been posted dozens of times before, most notably by UU brother PhilUSAFret.