Clarity on lifting of NOC

I am working in a company in Oman from 5 years. It doesn't gives NOC and recently they renewed my Visa for 2 years. I wanted to know if I wish to  change my Job after 1 Jan when NOC ban will be removed, can I do it or I will have to mandatorily complete the term.
PS they renewed it without my consent and months before expiry

you will be able to switch job starting from January 2021.
When you resign, then you have to complete 30 days notice according to Article 37 of Manpower Law:

https://www.manpower.gov.om/Laborlaw

Read both Articles 37 and 43.