They have a 1 year lease and have put down a $2250 security deposit.  

Of course, you always have the security deposit as well.One thing to consider is requiring the students' parents to co-sign the lease and be responsible for both the rent and potential damages.

If I am in no hurry I just give them a slot to do it in and they use it for fill in work.

For developers in Denver, City of Denver recently came out with some recommendations for tackling slot homes and rowhomes.

.- Money that you can fully source and paper-trail, such as by lining a $155,322.58 deposit up with a settlement statement from a home you sold that netted you $155,322.58. - Borrowed money that is secured by an asset, most commonly real estate.

I already made deposit for the closing In this case can i sue the seller and the real estate agent to comply they are not helping att all. 

If he can not close or assign the contract he risks forfeiting his earnest money deposit since he breached a contract.

If I sign a contract I plan on buying the property, so unless there is something wrong with the property itself, I am not worried about losing my deposit.

If at the end of a "deal" he presents you with a check, deposit it but don't use the money for a while in case it's false and bounces.

When investing in a property, you need to give at least 25% deposit to the bank for a buy to let mortgage.