If the father is Non gazetted officer belonging to class 3/4, Can we get an obc certificate?

Even though you are asking about the OBC certificate, I deduce that you are thinking about OBC Non-Creamy Layer Certificate. I will write about it.

Creamy layer is based on the status of your parents.

Creamy Layer

For the jobs under the Central Government, if the parents of an applicant entered the service as Class I officer before the age 40 (direct recruitment), the applicant is considered as a creamy layer.

Also, if both the parents of the candidates entered into service as class II officers, before the age 40 (direct recruitment), and entered into the service before the age of 40, the applicant is considered as a creamy layer.

 Non-Creamy Layer

Except for the above children of the above-mentioned employees, almost all get the benefit of “Non-Creamy Layer” Status.

• If your parents are not directly recruited Class1 (Group A) or Class2 (GroupB) officers OR they do not occupy any constitutional posts (like that of President, Vice President, Governor etc) you are most likely to fall under Non-Creamy Layer OBC.
• If your parents are not employed by the government, their income should be within the limits by the government to be treated as Non-Creamy Layer OBC.

In order to qualify as an OBC non-creamy layer candidate, the applicant’s parents’ annual income should be less than Rs. 8 lakhs.

Salary and agricultural income are not to be considered as income for calculating annual income for creamy layer status. As far as the Government employees are considered, the entry cadre/post is to be taken into consideration.

While applying the “Income/Wealth Test” to determine creamy layer status of any candidate, income from the salaries and income from the agricultural land shall not be taken into account. It means that if income from other sources other than the salary and agriculture exceeds the income limit, then only the candidates shall be treated as Creamy Layer.

So, as your father belongs to a class 3/4 officer and if your parent's income is below INR 8 lakhs, then you most likely belong to Non-Creamy Layer of OBC