IPSec for user to access the resources securely at the site where SRX is placed. I myself think its is only possible via SSL VPN with NCP client. but the user does not have that license. will the default IPSec vpn feature help in anyway.
There is a default 2 user license for remote access VPN on the SRX branch series. The details of how to use this and whether it is SSL or IPSEC vary with the specific model and version of Junos running on the device.
What is you rmodel and version?
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home
But they only mention the SSL variety which requires the NCP client as noted in the release notes. You can get a 30 day trial to confirm it meets your needs but will need a license for the software after that. The dynamic vpn allows 2 connections without a license on the SRX itself.