What is the maximum antenna cable length allowed in GNSS application?

Although this has nothing to do with amateur radio, this can be broken down to a general radio technology question.

So my concern is if i increase my antenna cable will there be any signal loss?

Of course! Nothing (aside from superconductors) is lossless.

I am using GNSS survey grade antenna for my GNSS receiver application testing,

I don't know what antenna that specifically is.

GNSS antennas tend to be active, i.e. actually an antenna plus an amplifier.

This tends to make reception pretty robust against cable losses – the signal is already amplified once it enters the cable.

No general statement on cable loss can be made: That's a key parameter of the coax you want to use, and differences over several orders of magnitude in loss for a cable of the same length but different specifications are not unusual.

What is the maximum antenna cable length allowed for GNSS signal?

No such thing can be stated. It depends on the acceptable loss – and that's a property of your antenna, its amplifier, and your receiver, and most importantly, how much SNR loss you're willing to accept.