Dr. Ir. (Achmed) Soekarno

All of these notes have the same Block letters (SDA1) in plate

There are many forgeries of this note, and there is no specific method to determine this note as genuine or fake.
The sharper the printing, the more chance it is a real note. However, this observation can only be undertaken if one has several notes to compare.

This note is of fairly sharp printing.

Conclusion: It could be genuine.