I have been approached by a UK construction company for a job of Civil Engineer.How to verify its authenticity

Question

I was offered this job after I had registered with Timesjobs.com.

Answer 1

It all looks real.  But, no proper recruitment company will;  

offer you a job with out an interview

want payment for work permits

want payment for a visa

charge you an administration fee

charge you for anything

ask for your bank details

So long as Timesjobs does not do any of the above, you should be all right.