Finally I got solution..It's working good...
select
cast(sum(datediff(second,FROMTIME,TOTIME))/3600 as varchar(12)) + ':' +
right('0' + cast(sum(datediff(second,FROMTIME,TOTIME))/60%60 as varchar(2)),2) +
':' + right('0' + cast(sum(datediff(second,FROMTIME,TOTIME))%60 as varchar(2)),2) as 'Total Hours',
CAST(sum(DATEDIFF(SECOND, FROMTIME, TOTIME)/28800.0) AS DECIMAL(5,2)) as 'Totaldays'
from TRNSWRKPROGRESS