Whether i should apply for TES 42 , I am conference out in NDA 142 ?

Definitely,if you want to join the defense forces then you should apply for every opportunity you get.
What if you are conference out ,there are many candiadates which are conference out and still repeating 5-6 times to join army

• Life is full of ups and downs you should stay motivated.
• You have to live a disciplined life to join army.
• You need to understand the reason why you were rejected and try to bring change in yourself.
• Try to have that discipline that is required by them.
• You can also join coaching for SSB,if required.
• I will suggest you to don't think just fill the form they will select you if you have that OLQs Officer Like Qualities.

I myself got rejected in TES 41 but I can't apply for TES 42 because I am above 19.
I hope that you will do your best and get selected.
You can refer various website to have knowledge about all the procedures.
Best of luck