Which of the following pairs of ions have same paramagnetic moment?

Cu²⁺, Ti³⁺

The paramagnetic moment of an ion is determined by the number of unpaired electrons in the ion. The more unpaired electrons, the greater the paramagnetic moment.

Cu²⁺ and Ti³⁺ both have 1 unpaired electron in the d orbital. This means that they have the same paramagnetic moment.

The other pairs of ions in the question, Ti⁴⁺, Ni²⁺, and Mn²⁺, all have different numbers of unpaired electrons. This means that they have different paramagnetic moments.

Here is a table of the electronic configurations and paramagnetic moments of the ions in question:

As you can see, Cu²⁺ and Ti³⁺ are the only ions with 1 unpaired electron. This means that they have the same paramagnetic moment.

So the answer is (1), Cu²⁺, Ti³⁺.