Meaningful output of FIR filter output I have implemented FIR filter using tapped delay line method. I start getting output as soon as first input sample is passed to it, I am wondering from which sample I will get the proper output(without transient outputs) from filter.

Does it depend on location of highest magnitude tap or it's just dependent on the length of filter.The number of filter coefficients I am using are N(odd) and symmetric. 
for verifying I took the following filter taps as example :-

$F1$ $=$ $[1 0 0 0 0 0 0];$

$F2$ $=$ $[0 1 0 0 0 0 0];$

$F3$ $=$ $[0 0 1 0 0 0 0];$
and so on,if I pass sine wave using filter coefficients $F1$ then the first sample of the output is itself meaningful but if I use $F2$ and $F3$ then meaningful output is from second and third output samples respectively. I am also wondering how matlab command $filter()$ works.
If it's a linear phase FIR filter, then the inputs signals will be shifted (delayed) by an amount of group delay at the output.

For a linear phase FIR filter of length $L = 2K+1$ the group delay will be $N = K$ samples. For even length $L = 2K$ FIR filters it will be at $N = (L-1)/2$ ; half-sample position.

For non-linear phase FIR filters, group delay will be dependent on the specific frequency of the applied input signals.  It should be computed from

$$ \tau = - \frac{d \phi(\omega)}{d\omega} $$

where $\phi(\omega)$ is the phase response of the filter. 

The matlab function filter(b,a,x) computes all the samples begining up to input signal length. So the first samples are transients.