The rate of tax is 18%http://www.cbec.gov.in/htdocs-cbec/gst/central-tax-notfns-2017
Last date for opting for composition as per the existing rule already over. It will be a great help to SMEs, if the last date is further extended.
GST registered parties need to file GSTR 3B on 20th August and 20th september for the transaction made during the month July and August respectively.
GSTR 3B can be dowloaded from www.gst.gov.in