what are the NTRU keysize and application in industry?
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.