Hi Chiru,
please check below configuration.
1. go to spro>crm>transactions>basic settings>define transaction types
2. mark your Z transaction type
3. in navigation bar on the left side click on Channel
4. add channel GUI CRM WEBCLIENT UI
and one more thing check inactive check box should be empty.
check below link also
http://scn.sap.com/community/crm/sales/blog/2013/08/23/quotation-transaction-type-not-shown-in-webui
http://scn.sap.com/thread/1648811
http://scn.sap.com/thread/2130867
regards,
vishwa.