The concept of Hell and Heavens is similar in all Abrahmic faiths. Hinduism is different, we can compare it with the religion prevalent in Arabia prior to Islam. As far as Krishna and Buddha is concerned we dont know who they were, could be very pious people (maybe Nabi’s) as we only know the name of the most famous few. After their deaths their teachings could have been perceived wrongly. Besides before Islam as per our belief’s all religions were based in particular areas and times.