6m trying 1 veggie/fruit a day for a couple of days. skipped intro to cereal due to bad diaper rash with rice. can i add cereal with the new food?

Yes: reintroducing rice cereal is ok. Make sure you introduce baby food longer than 2 days to make sure there is allergic reaction to baby food. Diaper rash associated with cereal could be incidental

Yes: You can add cereal at any time. Just remember to only add one new thing every couple of days - that way if they don't tolerate something, you will know what it is.