In seebeck whether electron moving from hotter to colder region creates potential or the heat itself cause atoms to be charged at an end? If without potential can a electron move from hot to cold end?
A temperature difference across a conductor's ends creates a potential difference.
The electrons at the hot end are thermally accelerated and gain more kinetic energy. An intuitive analogy is that they then "move around" more violently, so they "fill" more. Since they "fill" more on their limited space, they start drifting towards the other end, where electrons "fill" less (they are colder) where there is "more" space.
This tendency of electrons to drift from a hot to a cold end corresponds to an electric "push" from the hot to the cold end; in other words, it corresponds to a potential difference, usually called the Seebeck voltage $V_s$:
$\Delta T$ is the temperature difference and $S$ the Seebeck coefficient, a material property that indicates how well a material produces the Seebeck effect.