My passport is expiring after 6month,but iwant to renew it now by TATKAL service. Plz help me?

Contact your regional transport office. No renewals are done now. A new passport is issued which will require all the formalities which are necessary for new passport seekers. You can use legal fast track method with higher fees payment which an authorized passport agent or the regional office will tell you. Your old passport will be sent for verification to the office from where it was issued. The passport office for your region will have to wait for certain time for verification to be done after which they can start actions at their end. This will take some time, so better rush up.