How to find out the farrow coefficients if FIR coefficients are given?
There is no standard way to determine the coefficients of the Farrow structure for a given FIR filter. The Farrow structure is an implementation of a whole class of FIR filters with transfer function(s) $H_{\mu}(z)$ with a continuous control parameter $\mu$. Often this parameter $\mu$ determines a fractional delay, but it could as well be any other adjustable filter property.

The transfer function $H_{\mu}(z)$ of the Farrow structure is given by

$$H_{\mu}(z)=\sum_{k=0}^{K-1}C_k(z)\mu^k\tag{1}$$

where $C_k(z)$ are FIR transfer functions. From $(1)$, the impulse response is

$$h_{\mu}[n]=\sum_{k=0}^{K-1}c_k[n]\mu^k\tag{2}$$

So each filter coefficient (of the corresponding transversal filter structure) $h_{\mu}[n]$ is implemented as a weighted sum of coefficients $c_k[n]$. This is why there is no one-to-one mapping from given FIR filter coefficients to the coefficients of the Farrow structure.

You need to specify which filter property the parameter $\mu$ is supposed to control, and then you need to design the coefficients $c_k[n]$ of the Farrow structure accordingly.