Son has ADHD and is being bullied at school. Can we press the township to pay for a private school

There's really not enough information to answer.  Private school or an out of district placement only really occurs when the district cannot provide a free and appropriate public education within the district.  In many cases, there may be another school within the district that could accomodate your son.  For example, if there is more than one lementary school, he could be transferred to a different school within the district, but not the one he should be attending.  Having ADHD is difficult, and getting bullied is awful, but that's usually something the District is going to address "in house".