Hello @Techgaon,
We apologize for any inconvenience this may have caused. You can create the weight as a product attribute, assign it to the products, and you can filter it using the Filter Product by Attribute widget by placing it under the Shop Sidebar.
Alternatively, if you wish to filter by weight (under the Additional Information tab), you may need to consider a third-party plugin that better meets your requirements or contact the support team of the WooCommerce plugin for further advice.
Best Regards,
8Theme’s Team