The OBC Non creamy layer for the kids of government employees is decided on the basis of grade of post held by parents. Thus:

• If anyone of your, father or mother are direct recruited class 1 servants then you won't be eligible for NCL. But if he/she is promoted to class 1 then you could be eligible
• If both your parents are class 2 than you won't be eligible for OBC quota, but if only one of them is than you will not fall in the creamy layer.
• If your father was recruited direct to class 2 position and than promoted to class 1 before age of 40, the you will fall in creamy layer

The kids of the government servants who doesn't fall under the above category, fall in the NCL OBC category.

Dear Sir,

Income of your parents only will be calculated. Thus you can get the certificate.

The government will consider the parents’ status to determine “creamy layer” instead of status of the candidate applying for the job. In case of women candidates, too, the parents’ status will be considered and not the husband’s status.

Validity period

http://document.ccis.nic.in/WriteReadData/CircularPortal/D2/D02adm/36036_2_2013-Estt.Res-I-31032016.pdf

Please note that there is no validity period of OBC-NC Certificates.
The Department of Personnel & Training, clarified its position Govt. of India vide OM No. 36033/4/97-Estt.(Res.) dt. 25th July 2003.
It is only a misconception that there is a validity period of OBC-NC Certificate.
Thus OBC-NC Certificate is absolutely valid even if issued for more than 3 years ago but with a self - declaration given by the Candidate as per the format mentioned in the OM.

Find the link to the DoPT OM: 

http://ccis.nic.in/WriteReadData/CircularPortal/D2/D02adm/36033_4_97_01April2005.htm

EQUIVALENT POSTS FOR OBC CREAMY LAYER.. PLEASE VISIT FOLLOWING LINK CAREFULLY

http://www.ncbc.nic.in/Writereaddata/Supplementary%20Creamy%20Layer%20Report%20241115%20final%20at%20430PM%20Corrected%20by%[deleted]%20page%20no156

EQUIVALENT POSTS FOR OBC CREAMY LAYER.. PLEASE VISIT FOLLOWING LINK CAREFULLY

http://www.ncbc.nic.in/Writereaddata/Supplementary%20Creamy%20Layer%20Report%20241115%20final%20at%20430PM%20Corrected%20by%[deleted]%20page%20no[deleted].pdf

your what is your father status .? Was he class 1 officer in govt college before age of 40 

facts are are not clear 

state detailed facts of your case 

This is not the criteria for the purpose if his income or income of the family is more then Rs.08 Lac per annum then you are not entitle for the benefit if not then is. 

- To get an OBC NCL Certificate in Assam , the following conditions are :

1. The applicant should be a permanent resident of Assam.
2. The applicant is eligible if he/she belongs to the recognized community, i.e. must belong to OBC category.
3. The annual income of the applicant’s family or the annual income of the applicant’s parents should not exceed Rs.8 Lakhs including the income from other sources (Land, property, business). 
4. If ,parents are direct recruited class 1 Officer , then not eligible . But if promoted to class 1 then  is eligible for NCL
5. If, parent was recruited direct to class 2 position and then promoted to class 1 before age of 40, then fall in creamy layer

      -  Assistant/ Associate Professors is under the category of Class I/Group A .

      - Hence, in view of above , you are not elgible for getting the NCL OBC certificate .

      - Presently , you want to apply for getting the said certificate and your father is working as Assocoate Professor.

What is his income ? Creamy layer status examine by income and not designation. Only privilege class designation are consider to exclude from NCL status like judges,  IAS etc. 

Hi,

As per your inputs, you are not under NCL OBC

Yes if other factors of income is not going against you. 

What was his salary 

In light of the limited facts given you will not get the benefit of reservation 

See if the father is government class one employee then you shall not get the benefit.

Who are covered under Creamy layer of OBC Quota

(I) V.V.I.Ps.- President, Vice-President, Judges of the Supreme Court and of the High Courts etc.

(II) Government or PSU employees of Central or State-

(i) parents, either of whom is a Class I officer (direct recruits)

(ii) parents, both of whom are Class II officers (direct recruits)

(iii) parents of whom only the father is a direct Class II officer and he gets into Class I at the age of 40 or earlier.

(III) In military, parents, either of whom is in the rank of Colonel and above.

(IV) Persons engaged in Profession, Trade and Industry whose last three-year’s separate annual income is more then Rs. 4.50 lakhs per year.

(V) Families owns agriculture land having (i) ‘irrigated land’, more than 85% of the statutory ceiling area or (ii) The rule of exclusion will not apply if the land holding of a family is exclusively unirrigated.

(VI) Persons having separate gross annual income of Rs. 4.50 lakhs per year or above for a period of last three consecutive years excluding income from salaries & agricultural land.
 

For non government employees the income is criteria and if his salary is more then 8 lakh you shall not get the benifit

OBC Creamy layer—-Who has yearly income more than 8 lakhs or Government Employees of greater than class 3 are not eligible for OBC Quota. 

OBC Non-Creamy layer—– Who has a yearly income below 8 lakhs or Government Employees of Class 3 or below class 3 officers are eligible for OBC Quota.

This is a promotion to class I  category before 40 years of age hence I am afraid you may not be eligible for the concession under OBC NCL category. 

What was his income?

More facts would be required such as his class before 40 years, your mother's income etc.