You are not required to keep applications active for any particular period beyond receipt. Candidates will (properly) assume they are under consideration for the same or similar positions after submitting an expression of interest during a six month period if you say six months. Six months seems a very long time to have one position or one type of position open. Our recommendation to clients is to limit the period that any application is active. On your second question: If a candidate applies for a position, and an identical position is opened two months later, and you've told candidates their applications remain active for six months, it certainly appears that the candidates should be considered for the second opening. They may be dispositioned the same (i.e. they may still be found not minimally qualified, or not as well qualified because of experience, or whatever), but they should be considered. This is one of the problems in saying that applications are considered active for six months. You need to live by the rules you set. If you say "active for six months," then candidates (and regulatory agencies) will have the right to assume an application is in fact under active consideration for six months. I would strongly encourage you to move away from this six month period. We encourage clients to make candidates apply for each open position in which they are interested, and encourage clients to inform candidates that they must apply for individual openings in order to be considered for those openings. If you have a type of position that you fill routinely (i.e. assembler, welder, janitor, cook, laundry, call center person, etc.) where you have one constantly open requisition, then a six month active period may make sense. However, all candidates who apply definitely continue to be active for the six month period in such a situation. Also, constant (or "evergreen") requisitions are often associated with large back pay settlements.
You can use this OFCCP audit checklist to ensure you're doing what is required to maintain OFCCP's regulations including VEVRAA, Section 503, and EO 11246. Or request a demo to streamline your compliance and recruiting efforts.