The number of inter halogens from the following having square pyramidal structure is
$$ClF_3, IF_7, BrF_5, BrF_3, I_2Cl_6, IF_5, ClF, ClF_5$$

We need to identify which interhalogens from the given list have a square pyramidal structure.

A square pyramidal structure arises when a molecule has the general formula AX$$_5$$E$$_1$$ (5 bonding pairs and 1 lone pair), with sp$$^3$$d$$^2$$ hybridization.

First, consider ClF$$_3$$. Chlorine has 7 valence electrons, forming 3 bond pairs and retaining 2 lone pairs, which gives 5 electron pairs overall. Since the resulting AX$$_3$$E$$_2$$ arrangement corresponds to a T-shaped geometry, ClF$$_3$$ does not adopt a square pyramidal structure.

Next, IF$$_7$$ involves iodine having 7 valence electrons forming 7 bond pairs with no lone pairs, for a total of 7 electron pairs. The AX$$_7$$ arrangement corresponds to a pentagonal bipyramidal shape, so IF$$_7$$ is not square pyramidal.

Turning to BrF$$_5$$, bromine contributes 7 valence electrons, yielding 5 bond pairs and 1 lone pair to make 6 electron pairs. This matches the AX$$_5$$E$$_1$$ pattern and sp$$^3$$d$$^2$$ hybridization, resulting in a square pyramidal structure, so BrF$$_5$$ qualifies.

In contrast, BrF$$_3$$ has bromine with 7 valence electrons but forms only 3 bond pairs and 2 lone pairs—5 electron pairs in total—leading to an AX$$_3$$E$$_2$$ T-shaped geometry and thus not square pyramidal.

Considering the dimer I$$_2$$Cl$$_6$$, each iodine is bonded to four bridging chlorine atoms and retains one lone pair, producing a square planar arrangement around each iodine and giving rise to an edge-shared bioctahedral framework. Consequently, I$$_2$$Cl$$_6$$ is not square pyramidal.

For IF$$_5$$, iodine’s 7 valence electrons form 5 bond pairs plus 1 lone pair, totaling 6 electron pairs. The resulting AX$$_5$$E$$_1$$ configuration with sp$$^3$$d$$^2$$ hybridization yields a square pyramidal structure, so IF$$_5$$ is included.

As for ClF, the simple diatomic molecule has a linear geometry and obviously does not have a square pyramidal shape.

Finally, ClF$$_5$$ involves chlorine with 7 valence electrons forming 5 bond pairs and 1 lone pair, for 6 electron pairs in an AX$$_5$$E$$_1$$ arrangement. Therefore, ClF$$_5$$ also adopts a square pyramidal structure.

From the above analysis, the interhalogens with square pyramidal structures are BrF$$_5$$, IF$$_5$$, and ClF$$_5$$. Therefore, the number of interhalogens with square pyramidal structure = 3.