Query regarding insolvency and cheating

Sounds like you're stuck in a messy situation with A. Given A's IP has been dismissed, you might have grounds to file a cheating complaint, but it's not a straightforward yes/no.

The pending creditor IP against A could impact this. Talk to a lawyer ASAP to get a clear picture of your options and avoid wasting more money. They'll help you decide if filing a cheating case makes sense given your situation. 

To my knowledge, no offence of cheating could be alleged in the given facts.

Inform the police about dismissal of the IP and seek to register cheating case against A. If the police still don't register the case, approach jurisdictional magistrate court and file a private compliant and seek for court's cognizance in the case rather than direction to the police to register FIR. Hope this helps.

I am more skeptical about B than A. Earlier he dealt alone now wants to join hands to file  cheating case

Could it be because he had already filed a creditor IP? 

You can decide about joining B or ignore his request to join.

You know the situation and the prevailing circumstances hence you are the better judge to take a decision accordingly.

It is your personal decision to  join B or not. 

It is better to consult your lawyer or some other local prudent lawyer for proper analyses of facts / documents and professional advise.