Capital clause

by altering capital clause you are not affecting the liability of shareholder hence it's not treated as speacial business...
alteration of capital clause includes consolidation, sub-division ,conversion of shares into stock and vice versa and cancellation of uncalled portion...here the rights or liabilities of share holders are not affected and the liability of share holder diminishes in the last case...hence no need to go for SR and OR is enough

Agree with Ashwin Sir's answer. Also i would suggest you to go through the definition or relevant section of Special Resolution and Ordinary Resolution which may help you understand the same.