My spouse wants to join as a partner with his elder brother's sole proprietorship business. His elder brother has a CC loan mortgaged upon my spouse's vacant land. How will that be shown in their new partnership business?

On admission to the partnership firm, your husband is jointly and severally liability a per provisions of Indian Partnership Act.  Any property standing in the name of your husband will also come under the purview of partnership for any loan availed by the partnership firm. 

Yes but the CC loan is in the name of my husband's brother & husband himself is the guarantor of the loan being the owner of the land which has been mortgaged to get the CC loan. How will the same be displayed when they enter into a partnership business.