will i get placement if i do gp rating or cmcc course

i gave boards both 10th and +2 from wbbse board, i got 67% and the chance of not making it 60% in pcm is more than i will make it i think but overall i might have decent marks as my number in my 1st language english and cs is high...i really have to support my family so my choice was merchant navy now i am thinking of either getting into gp rating or cmcc my english percentage has been high through out the years in 10th it was 87% and in 3rd sem 99.9%tile or 36/40 (wbbse boards are now conducted in semesterwise), i have no other way to join merchant navy if i don't make it 60% in pcm i won't be able to sit for imucet, now if i join gp rating or cmcc in nusi goa or Ts rahman will i get placement tho? i saw some negative thing about it , after 6 months course will i get the job or it will not be worth it do i need sponsorship or smtg? can someone please help me out? or should i just apply for government job? will i get any government college? man i don't know what to do