Sub-domains within one and the same WP installation (multisite, for example) do not require a separate license. If you are going to use the theme on a separate WP installation you will need a separate license for each domain/sub-domain.
If you want to have a testing/staging platform, in this case, one and the same license can be used for both: testing and live.
Thank you for your response.
Please understand i have created a sub domain as refurbished.techyuga.com under sitegroup cpanel.
Then i was trying to use a duplicater plugin to clone techyuga.com data. However, as i don’t have enough space in my host they recommend me to use a fresh WP installation in sub domain.
Can i still use the same theme here? As this will be a single site only. Subdomain just reflect the different part of my business.