Hello

Your JEE mains second session has been scheduled  to be conducted on 18th, 19th, 20th, 22nd and 23rd July and as of now  there's no news about jee mains examination postponement  from NTA or MHRD officially , so nothing can be said about postponement with surety

But yes,

Now that,CBSE board examination has been cancelled ,according to sources   due to increase in covid 19 spread your jee main examination may be postponed too

but no decision has been taken about it yet, if it gets postponed then NTA or MHRD will notify about it , so till then you should continue and focus on jee main preparation

Thankyou