Observer

app->code->local->Gta->ExtraFeesRemove->etc->config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Gta_ExtraFeesRemove>
            <version>1.0.0</version>
        </Gta_ExtraFeesRemove>
    </modules>
    <global>
        <models>
            <gta_extrafeesremove>
                <class>Gta_ExtraFeesRemove_Model</class>
            </gta_extrafeesremove>
        </models>
        <events>
            <salesrule_rule_save_before>
                <observers>
                    <Gta_ExtraFeesRemove_Model_Observer>
                        <type>singleton</type>
                        <class>Gta_ExtraFeesRemove_Model_Observer</class>
                        <method>beforeSaveSalesRuleModel</method>
                    </Gta_ExtraFeesRemove_Model_Observer>
                </observers>
            </salesrule_rule_save_before>
        </events>
    </global>
</config>

app->code->local->Gta->ExtraFeesRemove->Model->Observer.php

<?php
    class Gta_ExtraFeesRemove_Model_Observer
    {
        public function beforeSaveSalesRuleModel(Varien_Enent_Observer $Observer)
        {
                      // How can i add condition    
        }

    }
?>

app->etc->modules->Gta_ExtraFeesRemove.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Gta_ExtraFeesRemove>
            <codePool>localhost</codePool>
            <active>true</active>
        </Gta_ExtraFeesRemove> 
    </modules>
</config>

Anyone help thanks.