Explain what features you can use to convert data in encrypted form in Tally ERP 9?

As per me, your question pertains to secure the company data using a password which is known as Tally Vault feature. By activating this option you can encrypt/secure company data from an unauthorized access or theft. 

You can use the Tally Admin Tool for this purpose. The complete process is quite complex. The link below explains the complete process. Make sure you have fimiliarity of TCP and TSF files.http://bit.ly/2dVlYmo