Yes, you can get a good Job in IT industry with Diploma in .Net from NIIT. NIIT is leading institutes in India, and diploma course from this institute provide immense of the opportunities.

If you have knowledge of one of following language then it will be very much beneficial for you:

Proficiency in NET
PROFICIENCY IN C#
PROFICIENCY IN ASP
PROFICIENCY IN HTML
PROFICIENCY IN XML
PROFICIENCY IN CSS
PROFICIENCY IN JAVASCRIPT
PROFICIENCY IN ADOBE PHOTOSHOP
PROFICIENCY IN DRUPAL 7.X
PROFICIENCY IN WINZIP 9 + (WINDOWS)

Following are the recruited of NIIT students:

Tata Consultancy Services
Capgemini
Paytronic Network Pvt. Ltd
HCL Infosystems
HCL Technologies
HDFC Bank
CEBS
TVS Infotech Webaccess
Infosys
Intarrvo Technologies
JK TECHNOSOFT
Kingmaker T Infra
Mahindra Satyam
Nelito Systems Net Access
Newgen Software