Do I need to consider both parents' income for OBC NCL?

I require clarification regarding my eligibility for the OBC NCL status under the "Viswakarma" caste (SL No. 161). My father currently serves as a Group A officer in government service, but he began his career as a Group C officer and transitioned to Group A after the age of 40. My mother is self-employed with a source of income. I would appreciate guidance on the following questions: 1) To claim my OBC NCL status, do I need to consider the income criteria for both parents, or is my father's government service status exempt from this income criterion? 2) If I need to account for the household income (both mother and father), should I consider their gross income or the net income after deductions (interest payments, losses, etc.) for the income criterion? I would be grateful for your assistance ASAP as the UPSC exam application deadline is approaching in 5 days. Thank you.