In some of the reactions thallium resembles aluminium, whereas in others it resembles with group I metals. Support this statement by giving some evidences.

Explanation

Similar to aluminium, thallium shows +3 oxidation state in compounds like `Tl_2 O_3, TlCl_3, Tl_2 (SO_4)_3`, etc. It forms complex `[TIF_6]^(3-)` similar to that formed by aluminium,`[AlF_6]^(2-)`
Due to inert-pair effect, it also exhibits oxidation state of +1 as exhibited by alkali metals of group 1. Some of its compounds formed in this state are `Tl_2 O , TlCl` etc., which are similar to the compounds like `Na_2 O, NaCl` etc. Like `Na_2 O, Tl_2 O` is strongly basic. Thus, it resembles group 1 metals also.