My parents got their green card through me last year , came to USA ( stayed here 3 months ) went back to India this January with the intention of returning back in less than 6 months. Right now corona virus is spreading everywhere, they are both old , 75-80 year old , with health issues and I don’t feel comfortable in them traveling back to USA right now , it might take more then 6 months in India ( while corona subsides in best case scenario) exceptional circumstances , otherwise I would have applied advance parole before they left , I don’t think I can apply advance parole while they are in India , can I send uscis a letter , I see some places it’s written that you can stay 6 months to one year without advance parole ( ideally less than 6 months ) at worse the naturalization process will be delayed , am I taking a big risk for their re- entry or it’s okay or is there anything I can do short of them coming back before 6 months are up , sorry for the long story , appreciate genuine feedback