Short answer. Yes. Discharge may be sought wholly or in part. Where you seek to free one particular property, the counter-bond is equal to the value of that property as determined by the court, rather than the full amount fixed in the order of attachment.
What the law says
But if the attachment is sought to be discharged with respect to a particular property, the counter-bond shall be equal to the value of that property as determined by the court.
Rule 57, Section 12 — Discharge of attachment upon giving counter. Read the full provision →
Partial discharge is expressly allowed
The party whose property has been attached, or the person appearing on his behalf, may move for the discharge of the attachment wholly or in part on the security given. That phrase is what makes selective release possible. It matters in practice because a writ often catches several assets at once, only one of which you urgently need freed, whether to complete a sale, keep a business running, or release an account used for payroll. You do not have to raise security covering everything in order to free the one item that is actually causing the damage.
How the amount is calculated
There are two different measures, and knowing which one applies is the whole point. For a discharge of the attachment as a whole, the cash deposit or counter-bond is in an amount equal to that fixed by the court in the order of attachment, exclusive of costs. For a discharge as to a particular property, the counter-bond is equal to the value of that property as determined by the court. Where the attached asset is worth far less than the sum claimed in the action, the second measure can be dramatically cheaper.
Cash deposit or counter-bond, and what it secures
The rule gives two ways to provide the security: a cash deposit, or a counter-bond executed to the attaching party and filed with the clerk of the court where the application is made. Either way the court acts after due notice and hearing. In both cases the deposit or counter-bond secures the payment of any judgment that the attaching party may recover in the action. Once the discharge is ordered, the property, or the proceeds of any sale of it, is delivered to the party who put up the security, which then stands in place of the property released.
The valuation is where the argument happens
Because the counter-bond for a particular property is pegged to that property's value as determined by the court, the valuation becomes the contested issue. The attaching party has an obvious interest in a high figure and you in a realistic one, so come to the hearing prepared to support the value you propose. Note as well that if the counter-bond is for any reason found to be or to become insufficient and no additional counter-bond is filed, the attaching party may apply for a new order of attachment.