This is a double displacement reaction that will form solid aluminum nitrate and aqueous cobalt(II) nitrate.

The balanced equation for the reaction is:

3Co(NO3)2 + 2Al(NO3)3 → 3Co(NO3)3 + 2Al(NO3)2

This reaction can be represented as a total ionic equation:

3Co^2+(aq) + 6NO3^-(aq) + 2Al^3+(aq) + 6NO3^-(aq) → 3Co(NO3)3(s) + 2Al^3+(aq) + 6NO3^-(aq)

And the net ionic equation is:

3Co^2+(aq) + 6NO3^-(aq) + 2Al^3+(aq) → 3Co(NO3)3(s) + 2Al^3+(aq)