NY state has a website for graduation rates for all high schools in the state, you can google it
Ramapo High School has a 63% graduation rate in 2014
Edward R Murrow A high School in Flatbush Brooklyn graduation rate is 81% (I dont know the name of the High School in Williamsburg or Boro Park, but Ive passed Murrow many times so I know that one and its in a jewish park of Brooklyn)
Harvard if you can get into it does not make cost an issue, their endowment is large enough to pay for any student who cannot afford it (Its the only Ivy League School like that)
Most colleges have some sort of financial planning so not everyone has to go to a community college, the City and State universities are fairly inexepensive and good