Dear Kshitij Gaur,
Hybridization is a hypothetical phenomenon in which orbitals of similar energy mix and form equal no. of orbitals of equal energy and are termed as hybrid orbitals.
In hybrid orbitals one e should present sothat other e from another atom with opposite spin will form bond.
If hybrid orbital will have two e or no e bond pair will not formed. To form bond pair or form bond two orbtals should overlap andmust contain one e.
Regards