There is no syllabus mentioned in AIIMS entrance exam of clinical embryology don't waste time searching for it.go to e commerce website like Amazon to buy sample books that are available in the market by various publications if it necessary to you or just make your zoology part strong and u will be able to attempt the answers as said by previous students.you need to read these too along with it

1.basic chemistry formulas

2.MOLECULAR BIOLOGY

3.BIOMOLECULES

4.inderbir singh for embryology as this book has very easy language.

All the best for your future