From (3), K is the middle term.
___ ___ ___ _K_ ___ ___ ___
From (4), there must be exactly 2
numbers between J and M which gives two possible positions.
 ___ _M_ ___ _K_ _J_ ___ ___
 ___ ___ _M_ _K_ ___ _J_ ___
From (1), the number of letters between
O and K must be same as the number of letters between M and L. Also, the number
of letters between them can be 1, 2 or 3. Using trial and error, it can be
found that there must be 2 letters between them. Also, it is possible only in
option  above.
 ___ _O_ _M_ _K_ _L_ _J_ ___
From (2) Z must be the highest and the
remaining N must be the lowest number.
_N_ _O_ _M_ _K_ _L_ _J_ _Z_Thus, the sequence of letters from the lowest value to the highest value