Getting into the marriage I knew I would have to chip into the debt (mortgage/loan) my husband had- and I was OK with it. I didn't have any debt of my own.
I also knew my inlaws weren't doing so well financially and were having trouble maintaining their business and paying mortgage on their house and 2 additional properties

That being said - fastforward 6 months the situation seems to have worsed.
They have borrowed money from us in the past and returned it later.
Now they want my husband and my bro-in-law to take over the mortgage of the 2 additional properties by transferring the deed on their name.

This has made me a bit nervous - since both the mortages together will mount to a substantial amount monthly. Also since we have a loan of our own which we find hard to pay every month. My father-in-law wants us to take responsibility of the other properties since he does not want to loose them in case he faces bankcruptsy tomorrow.
Both the properties are NOW under value as well.

Also we find to difficult to make any saving as our own - since we have to help them out pump money in the business - which is essentially failing.

Does it make sense to refinance them?
In future if they ask for a cash loan - how do we position ourselves without offending?

You can't take over mortgages - you would probably have to refinance.

Can your credit take the hit? Do you want to get yourself in this position? First family argument, who knows what will happen. Does your husband want, basically, to be in business with his brother? What if the brother falls on hard times - is the mortgage payment all "yours"?

This would make me a LOT nervous.

It sounds mean but any time I lend family money I get it on paper - I know, it's family, but I've been burned before.

If the business is failing maybe now is the time to close it.

I think you are walking on a razorblade here. They are family. You "married in." That doesn't mean you can be stupid or put your own financial future in jeopardy.

I wouldn't do it - but that's just me.

The brother is already in hard times- he just lost the job- the payment is all ours.. now

So your husband has to look and say no, you can not always pay everyone's bills,

If they made poor money choices it does not mean they have to take everyone down with them.

Tell them to see the property, or let it foreclose and you will be there to help them after that.

My husband is against saying no- being parent n all... and I understand his point of view.. I am not sure what I need to do- since the inlaws didn't even bother getting my opinion before makign this decision

I already told you what I would do - I would NOT put my financial situation in jeopardy foolishly. Say the unforgivable happens and you and your husband split up. Do you want to handle the "he owes a lot of money to the bank so there's none to pay bills" question then?

He's your husband. If he speaks for both of you and says yes, well, then there's little you can do.

If your name isn't on the mortgage or deed or anything else keep in mind that YOUR income is being used to pay other expenses while household money is being used to pay this mortgage.

What is the family business? Do these additional properties produce income that will support a refinanced mortgage?

You also may want to explore keeping your money separate so you have an out.

It's always hard to say no to family, but sometimes you have to. You need to put your own family (you and your husband and your children) first. Your husband needs to understand that to and talk to his parents that you both cannot afford to pay the mortgage on their business.
You need to sit down with your husband and make it clear to him that you do not agree to pay his families debts.
I also agree with Scott, have your money separate from your husbands. You might want to file separate tax returns so you won't be liable for your husbands debts if he goes through with this plan (unless you live in a community property state).