Need Proper Advice from Seniors

I just completed my 11th class as a Maharashtra Board Student. (PCM and CS are my subjects) And I am also preparing for JEE. Me abhi regular school me hu and school wale practicals, journals, completion and mainly attendance ki wajah se bohat tang krte hai. Should I join a dummy school? Ya fir regular se he continue karu?? And agar me dummy school join krta hu toh boards ke liye kese padhu ek genuine advice dedo chota bhai samaj ke.