My nokia is not accepts sim card, when i insert sim card it says SIM CARD INVALID? i m from pakistan plz help me,this cell is brought from koria

The phone is probably sim locked.

If the Nokia X6 16GB phone,displays invalid sim card message on the screen it is locked to some network.Please find out the network and country it is locked now.If it is locked to network,it will not accept other network sim card.But you saying it is accepting other networks sim card.How many network sim card have tried inserting in it?If you tried only one network sim card and it accepted that it is locked to that network.You can also try using some other network sim card.If it displays invalid sim message again.It is under network lock.To unlock it use unlock code.Visit the site Wickedunlock.com get code and unlock it easily.

It's says INVALID SIM means it locked to Network ,you need to Unlock it....You can get the unlock code from here
Theunlockspot.com
and Unlock it from Network lock,then you can use with any GSM Network Sim card.

you can check it with other sim card ,if it remains the same problem ,it may be locked to particular network wont accept any sim card other than the particular network ,you can unlock it and used to other network,try here http://www.theunlockarena.com/nokia-6730-classic/rs13wp9/

There should be no problem in using the phone in Pakistan unless it is locked to a particular service provider. If so, then have it unlocked and start using it. Since it is a quad band it should work in pakistan.

it may be due to network lock, contact service provider , else you can get unlock codes here http://www.onlinegsmunlock.com/nokia-n97/rs7wp9/
you need to specify network provider

try unlocking sites

i have a china made mobile n8 but after inserted it shows invalid sim what's the solution of this problem

Try restriction codes here http://www.superunlockcodes.com/nokia-6700-classic/rs12wp9/

You will need to take it to a phone store and get it unlocked it is locked to a uk network.