I have got a stream in techno India Salt lake in the first counseling of wbjee. But I want another college, then what should I do now??

If you want to get other college other than that you have got in the first round of counseling, you have to do yes upgradation. By this,  you will be eligible for 2nd round counseling. For this you have to be present physically in the reporting centre.
If you don't want to upgrade to the 2nd iteration, in that Case you have to do no upgradation.
You have to be present physically at the reporting centre for this too.
Hope you understand.
Good luck...

Hello student

If you want to get admission in some other college then you have to float your filling choice there is two option one is freeze and another is float and any have to choose float.

All the best!