Related work in an article
If you're writing a conference paper, put it in the same place as it appears in the conference papers you read.  If you're not reading any conference papers, you're not ready to write one.

If you're writing a journal paper, put it in the same place as it appears in the journal papers you read.  If you're not reading any journal papers, you're not ready to write one.

If you're writing a dissertation, put it in the same place as it appears in the dissertations you read.  If you're not reading any dissertations, you're not ready to write one.

If you're writing a $PAPER_TYPE, put it in the same place as it appears in the $PAPER_TYPEs that you read.  If you're not reading any $PAPER_TYPEs, you're not ready to write one.

Also: Ask your advisor.