Both your visas (175) are valid for 5 years and the expiration date is shown in the visa label. It does not matter if your husband moves to for a couple of months while you stay in Australia. Or both of you move to India for a couple of months. You are allowed to enter and leave Australia as many times. The visa validity becomes a concern when it expires. As long as you stay in Australia when the visa expires, you are still a permanent residence and can stay indefinitely. However, if you want to leave Australia and to return back, you need a valid Australian visa. If your visa expires before you leave Australia, make sure you apply for a resident return visa (RRV). More information can be found in immi.gov.au You do have to meet the residential requirements as stated to determine what RRV you will qualify for.