Hi Dolly,
Yes, you can upload the trial balance directly into the GL using a General Journal. However, I'd suggest the following:
a) Don't use an offset account. Since you're migrating the closing balances of each account, simply enter the balances (DR or CR) without an offset account and post them in a single journal voucher. As long as all balances are entered correctly, the journal should balance.
b) For subledgers (customers, vendors, inventory, fixed assets, etc.), record both a debit and a credit for the same amount. This creates the required subledger transactions while having no net impact on the General Ledger. Alternatively, you can use a temporary offset account (for example, 99999) to offset the subledger balances during the migration.
Cheers,
Burhan