Unexpected output from TPS73633 LDO
post a schematic of your board would be helpful.

I would try a few things:

1) make sure that the layout matches the schematic;

2) make sure that the chip is real;

3) make sure that the battery provides the right voltage output when connected to the board;

4) make sure that the battery is correctly connected to the board;

5) make sure that your meters are accurate;

6) make sure that the chip is soldered on correctly;

7) put a small load to the ldo output;

...

basically, make as few assumptions as you can and start with the things that you are the most sure about.