If I give NET exam this Nov, will I be eligible for next year (2019), as I will get my masters results in 2019 May?

So the validity of UGC/CBSE NET is unlimited or there is no expiration date. UGC JRF is valid for 2 years from the announcement date of the result or from the issue date of the certificate and UGC lectureship is valid for lifetime up to the date of your retirement age.