Hi Manoj,
For HR challans, the terms required for PF and ESIC are essential. According to PF and ESIC laws, as well as some other laws, every organization has to fulfill statutory requirements such as monthly returns. Related to PF and ESIC, it involves monthly returns, Factory Act returns, minimum wages returns, and unpaid wages returns, among others.
To fill up these returns, the term used is "Challans." Returns are paid to the Assistant Commissioner's office of the particular region. This kind of question is expected from freshers!
I hope this helps clarify the process for you. Let me know if you need further assistance.