Is 6500 SGD good enough for a family of 2 ?

I don't know what "SGD 6500 in principle" means, but the figure is sufficient (but by far not luxurious) for a couple. Of course the details (and your level of misery) depends on your lifestyle choices and how flexible you are in adapting to the local situation.
Please note that S$6000/month or more is required to get a DP for your partner, because that is also the minimum needed to survive.

thanks Beppy.. employer has said that is by far the max he can offer and will apply for EP for 2 years(which is max as per MOM-->told by HR)

My real concern is .. Is 6500 decent for an employee with 8+ exp in IT/Telecom . Any leads would be appreciated .

You should compare it with salary listings in surveys published by certain consultancies.
There was a thread about this (with links) a while ago in this forum.

You should start reading older threads, we have said numerous times that it depends on demand and supply. If a particular white collar job’s role & responsibility is in higher demand but short of manpower in Singapore then offered salary could be higher.

As Beppi said, check the paycheck and market comparison in Singapore to understand the average market salary of a role which you are offered.

S$6.5k for two people will be decent and can save nearly S$1.5k to S$2k depending on your expenditure. Good luck