H-1B visa is reserved for "specialty occupations." Those that require a at least a bachelor's degree in a specific subject or closely related subjects.
The period of time when an F-1 student’s status and work authorization expire through the start date of their approved H-1B employment period is known as the "Cap-Gap".
As reported by The Indian Express:
The proposed changes in the issuing of H-1B visas, the highly sought after US work permits, will badly affect the Indian IT firms which depend heavily on these work visas.
The changes under the Comprehensive Immigration Reform (CIR) put a curb on use of H-1B visa for those companies which have a higher ratio of work force under this category.
Most of the Indian companies will fall under this classification.
U.S. Citizenship and Immigration Services (USCIS) reached the statutory H-1B cap of 65,000 for fiscal year (FY) 2014 within the first week of the filing period, which ended on April 5, 2013. USCIS also received more than 20,000 H-1B petitions filed on behalf of persons exempt from the cap under the advanced degree exemption.