For crossovers, you have to design them yourself and build them by point-to-point soldering. PCBs are usually hard to make, or bad, for crossovers, given the kind of currents they have to handle. You can of course always buy crossover PCBs from LRoad or their equivalent in any city in India. You'll get "12 dB/octave 2-way crossover" PCBs all over the place. These PCBs are designed for one coil and one cap (typically electrolytic) per driver, and are useful for the hypothetical "8-ohm" speaker with a flat impedance curve, which does not exist in reality. Such crossover designs, and therefore their PCBs, are not worth anything --- if that's what you want, it's better that you buy factory-made speakers and enjoy the music.
And about cabinets --- I don't know of any place in India which builds good quality cabinets. Such things don't exist for a very good reason: there isn't any demand for even 10 identical pieces of any cabinet model. Therefore, no one will make cabinets and stock them, hoping you'll come along and buy some. The only way for a DIYer to get cabinets is to get them made. Carpenters are easily available in Indian cities, and though some may not be as talented as Hiralalji, they will often be willing to work with you and build something, if you sit with them and guide them.
Once again, factory-made cabinets are available, but they are not going to work for anything other than the mythical "12-inch woofer and 1-inch tweeter" type of design, i.e. a design where the cabinet design has not been factored into the speaker design at all. Such cabinets are available dime a dozen and are used in all our puja pandals and political rallies for blaring music or worse. You can't use those cabinets for making anything even passable for home use.
Crossovers and cabinets... make them yourself
For crossovers, you have to design them yourself and build them by point-to-point soldering. PCBs are usually hard to make, or bad, for crossovers, given the kind of currents they have to handle. You can of course always buy crossover PCBs from LRoad or their equivalent in any city in India. You'll get "12 dB/octave 2-way crossover" PCBs all over the place. These PCBs are designed for one coil and one cap (typically electrolytic) per driver, and are useful for the hypothetical "8-ohm" speaker with a flat impedance curve, which does not exist in reality. Such crossover designs, and therefore their PCBs, are not worth anything --- if that's what you want, it's better that you buy factory-made speakers and enjoy the music.
And about cabinets --- I don't know of any place in India which builds good quality cabinets. Such things don't exist for a very good reason: there isn't any demand for even 10 identical pieces of any cabinet model. Therefore, no one will make cabinets and stock them, hoping you'll come along and buy some. The only way for a DIYer to get cabinets is to get them made. Carpenters are easily available in Indian cities, and though some may not be as talented as Hiralalji, they will often be willing to work with you and build something, if you sit with them and guide them.
Once again, factory-made cabinets are available, but they are not going to work for anything other than the mythical "12-inch woofer and 1-inch tweeter" type of design, i.e. a design where the cabinet design has not been factored into the speaker design at all. Such cabinets are available dime a dozen and are used in all our puja pandals and political rallies for blaring music or worse. You can't use those cabinets for making anything even passable for home use.