The simplest form of ln is this to create a symlink:
cd /home/tuna/myfolder
ln -s /home/tuna/objects/oops.c
cat oops.c     # This will print the file
What exactly do you mean when you say "when I look it is empty"?
An extract from ln's man page, just to clarify things:
   ln [OPTION]... [-T] TARGET LINK_NAME   (1st form)
   ln [OPTION]... TARGET                  (2nd form)
   ln [OPTION]... TARGET... DIRECTORY     (3rd form)
   ln [OPTION]... -t DIRECTORY TARGET...  (4th form)
Your original code is the 3rd form which tries to create a symlink to /home/tune/objects/oops.c in the folder oops.c.
You should use the 2nd form which creates a symlink called oops.c in the current folder, pointing to home/tuna/objects/oops.c.