Relax. Firstly, bilingual children often get to speech a little later than unilingual children, because they have double the amount of grammar and vocabulary to process.

Secondly, he doesn't seem to be autistic - he doesn't throw tantrums and relates to other people. He may just be more used to adults who are generally more predictable than toddlers and he doesn't want to deal with other toddlers who might bite.

If he smiles and laughs occasionally, I'd let him find his own way and yes, if you can, put him in a Montessori nursery.