article 226 or 32 of constitution of india 1950 . anyone can file these writs in high court or supreme court for public interest . pil only for public interest not individual persons. you can file for public benefit if you find any activity which not in public favor and cause any harm and loss for society you can file writs in court .any normal person cam file pil .like example . people smoke in public, poor people condition , or any institute or university or company discriminate with any cast , religion, society or person . you can sue and file against. so basically pil is only for public not individual problem.