Without appointment you should factor in to go at least 2 hrs before
But like
@forw.jane mentioned postal application ke liye sirf self attested signed copies he chahiye
The original document requirement comes at a time when you go in person and they ask you to show the originals at the counter.
With postal application you are already paying top dollars, they will not require originals to be submitted by post.
and an after thought, BLS only has a mandate to handle Indian issued paperwork (like SC, PP, PCC, OCI, Visa etc), why put your Canadian issued originals in post/in their hand ? what if they loose that? they will absolve themselves of te responsibility and ping pong will begin ke Purolator lost the documents it wasn't them blah blah..
@forw.jane - Ctrl C + Ctrl V