You need to keep the Cockies and the Love Birds in separate cages. The Lovebirds are an aggressive species while the Cockies are very docile which means they will be bullied and possibly hurt by the more aggressive Lovebirds.
So please separate these birds into two cages one for the Cockatiels and one for the Lovebirds because eventually, the Lovebirds will hurt your Cockies. Make sure cages are large enough so the birds can spread their wings out and flap without hitting anything around them including each other.