what are the NTRU keysize and application in industry? I'm a student currently working on a research project on the NTRU cryptosystem, I've read some papers about this cryptosystem, and in those papers they are talking about keysize, is it the size of the public key or private key ?

is there any other indusctrial application of NTRU apart from CyaSSL ?
Usually, in public-key cryptography, the "key size" is implicitly referred to the size of the public key.

In the case of NTRU, both public and private keys are conveyed by the same thing: polynomials defined over a specific polynomial ring. These polynomials can be  represented as vectors in $\mathbb Z_q$ of size $N$. Therefore, raw public and private key will have the same size ($N \cdot \lceil\log q\rceil$ bits). For instance, with $N = 1171$ and $q = 2048$, which are recommended parameters, public and private keys are of size 1.57 KB.