Hello, Dhruv,
It is recommended to use a graphics editor and prepare product images (make them the same size) before uploading images to your media gallery; or use the Crop option for images. Read more – https://www.8theme.com/documentation/xstore/woocommerce/product-images/
This is independent of the theme, settings for images come from WooCommerce plugin, if our recommendation doesn’t suit you, please contact the support of WooCommerce.
Kind Regards,
8theme team