Magnetic moment of [Ti(H₂O)₆]⁴⁺, [Mn(H₂O)₆]²⁺ and [Cr(H₂O)₆]³⁺ can be represented as X, Y and Z. They are in order of

In [Ti(H₂​O)₆​]⁴⁺, oxidation state of Ti = +4 electronic configuration = d⁰ number of unpaired electron = 0

In [Mn(H_2​O)6​]2+ ,oxidation state of Mn = +2 ,electronic configuration = d⁵ number of unpaired electron = 5

In [Cr(H_2​O)₆​]³⁺ oxidation state of Cr = +3 electronic configuration = d³ number of unpaired electron = 3

Magnetic moment is directly proportional to the number of unpaired electrons.

Hence, the of magnetic moment becomes X<Z<Y