The Integration of Kashmir is not a case study of political integration in India because Kashmir is a disputed territory between India and Pakistan.

The Integration of Sikkim was completed in 1975 when Sikkim became the 22nd state of India.

The Integration of Goa was completed in 1961 when Goa became a union territory of India.

The Integration of Hyderabad was completed in 1948 when Hyderabad became a state of India.

Sikkim's strategic location was the main reason for its Integration with India. Sikkim is located in the Himalayas and borders China and Nepal. Its strategic location makes it important for India's security.

Goa's strategic location was the main reason for its Integration with India. Goa is located on the west coast of India and has a long coastline. Its strategic location makes it important for India's security.

Hyderabad's strategic location was the main reason for its Integration with India. Hyderabad is located in the center of India and is surrounded by several states. Its strategic location makes it important for India's security.

Sikkim's resistance to Integration was the main challenge faced during its Integration with India. The Chogyal of Sikkim, Palden Thondup Namgyal, was initially opposed to Integration. However, he eventually agreed to Integration after a referendum was held in Sikkim in 1975.

Portugal's opposition to Integration was the main challenge faced during the Integration of Goa. Portugal refused to recognize India's claim to Goa and even sent troops to defend the territory. India eventually annexed Goa in 1961 after a military operation.

Hyderabad's resistance to Integration was the main challenge faced during its Integration with India. The Nizam of Hyderabad, Osman Ali Khan, was initially opposed to Integration. However, he eventually agreed to Integration after a military operation was launched by India in 1948.

The Integration of Sikkim was a success because Sikkim's people were willing to join India. This was evident from the referendum held in Sikkim in 1975, in which a majority of the people voted in favor of Integration.

The Integration of Goa was a success because Goa's people were willing to join India. This was evident from the opinion polls conducted in Goa in 1961, which showed that a majority of the people were in favor of Integration.

The Integration of Hyderabad was a success because Hyderabad's people were willing to join India. This was evident from the referendum held in Hyderabad in 1948, in which a majority of the people voted in favor of Integration.

The case studies of political integration in India show that political integration is a complex process. It involves a number of factors, including the willingness of the people to join India, the opposition of other countries, and the military preparedness of India.