I noticed this query remain unanswered since 2018. I have just now noticed. Answering now may not be needed now in 2025. However, in case still you require assistance,
Pl.go thru' these links for help where you'll find useful guide to your requirements -
https://www.citehr.com/595190-filing-karnatakas-annual-return-form-20-enough.html
https://www.citehr.com/591305-how-2017-amendments-karnataka-factories-rules-impact.html#2370386
https://www.citehr.com/606319-struggling-file-annual-return-online-under-karnataka.html
https://www.citehr.com/601152-how-do-i-submit-form-21-online.html
https://www.citehr.com/232083-submission-deadline-half-yearly-return-under-factories.html
https://www.citehr.com/576741-navigating-esic-returns-half-yearly-submission-must.html
Under the Karnataka Factories Rules, the half-yearly return for factories is filed in Form No. 21, requiring factory managers to submit details on worker attendance, employment numbers, installed horsepower, and other key operational data to the Area Inspector by 30 days after the close of the half-year (June 30th and December 31st).
If you would require anything more you may continue this thread.