Earlier your question was---
Please explain - are the oxidation state and covalency of Al in [AlCl(H2O)]2+ same?
Here you are asking for a complex AlCl(H2O)5]2+
For this complex the covalency of Al is 6, as it is bonded with one chlorine and five H2O ligands.
In this case the given answer is correct.
We hope that clarifies your query.