can start brown rice. i started dear son with brown rice cereal 1st. asked pediatrician and he said is definitely alright to do so since brown rice is also rice. just rmb dont intro oatmeal, barley, wheat before you intro rice. it is advisable to startnew food in the day in case of allergic cos some allergic symptoms will show as early as few hours later.
maybe you can prepare some homemade puree and freeze them? bring a portion down to the fridge to thaw a night before. next morning heat up and feed. i used to put in a breast milk bottle for thawing and place it into a cup of hot/warm water to warm it, mix in the cereal and feed dear son.