In lib i'm adding jar(jtds:1.2.6.jar) file . 
But it's getting an error like: 
cannot load your jar file
sql.groovy :
package com
class Sql {
    String project
    String title
    static constraints = {
        project blank:false
        title blank:false
    }
}
Datasource.groovy
dataSource {
 pooled = true
     driverClassName = "net.sourceforge.jtds.jdbc.driver"
    username = "sa"
    password = ""
    dialect = "org.hibernate.dialect.SQLServerDialect"
}
hibernate {
    cache.use_second_level_cache = true
    cache.use_query_cache = false
    cache.region.factory_class = 'net.sf.ehcache.hibernate.EhCacheRegionFactory'
}
// environment specific settings
environments {
    development {
        dataSource {
            dbCreate = "update" // one of 'create', 'create-drop', 'update', 'validate', ''
      url = "jdbc:jtds:sqlserver://ASIA-IN-GJVX022:1433;databaseName=Haritha;instance=SQLEXPRESS"
        }
    }
    test {
        dataSource {
            dbCreate = "update"
            url = "jdbc:h2:mem:testDb;MVCC=TRUE;LOCK_TIMEOUT=10000"
        }
    }
    production {
        dataSource {
            dbCreate = "update"
            url = "jdbc:h2:prodDb;MVCC=TRUE;LOCK_TIMEOUT=10000"
            pooled = true
            properties {
               maxActive = -1
               minEvictableIdleTimeMillis=1800000
               timeBetweenEvictionRunsMillis=1800000
               numTestsPerEvictionRun=3
               testOnBorrow=true
               testWhileIdle=true
               testOnReturn=true
               validationQuery="SELECT 1"
            }
        }
    }
}